1
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Oz M, Lorke DE, Howarth FC. Transient receptor potential vanilloid 1 (TRPV1)-independent actions of capsaicin on cellular excitability and ion transport. Med Res Rev 2023. [PMID: 36916676 DOI: 10.1002/med.21945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 01/17/2023] [Accepted: 02/26/2023] [Indexed: 03/15/2023]
Abstract
Capsaicin is a naturally occurring alkaloid derived from chili pepper that is responsible for its hot pungent taste. Capsaicin is known to exert multiple pharmacological actions, including analgesia, anticancer, anti-inflammatory, antiobesity, and antioxidant effects. The transient receptor potential vanilloid subfamily member 1 (TRPV1) is the main receptor mediating the majority of the capsaicin effects. However, numerous studies suggest that the TRPV1 receptor is not the only target for capsaicin. An increasing number of studies indicates that capsaicin, at low to mid µM ranges, not only indirectly through TRPV1-mediated Ca2+ increases, but also directly modulates the functions of voltage-gated Na+ , K+ , and Ca2+ channels, as well as ligand-gated ion channels and other ion transporters and enzymes involved in cellular excitability. These TRPV1-independent effects are mediated by alterations of the biophysical properties of the lipid membrane and subsequent modulation of the functional properties of ion channels and by direct binding of capsaicin to the channels. The present study, for the first time, systematically categorizes this diverse range of non-TRPV1 targets and discusses cellular and molecular mechanisms mediating TRPV1-independent effects of capsaicin in excitable, as well as nonexcitable cells.
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Affiliation(s)
- Murat Oz
- Department of Pharmacology and Therapeutics, Faculty of Pharmacy, Kuwait University, Safat, Kuwait
| | - Dietrich E Lorke
- Department of Anatomy and Cellular Biology, College of Medicine and Health Sciences, Khalifa University, Abu Dhabi, United Arab Emirates.,Center for Biotechnology, Khalifa University of Science and Technology, Abu Dhabi, United Arab Emirates
| | - Frank C Howarth
- Department of Physiology, College of Medicine and Health Sciences, UAE University, Al Ain, United Arab Emirates
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2
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Kesner AJ, Lovinger DM. Cannabis use, abuse, and withdrawal: Cannabinergic mechanisms, clinical, and preclinical findings. J Neurochem 2021; 157:1674-1696. [PMID: 33891706 PMCID: PMC9291571 DOI: 10.1111/jnc.15369] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 04/12/2021] [Accepted: 04/12/2021] [Indexed: 12/14/2022]
Abstract
Cannabis sativa is the most widely used illicit drug in the world. Its main psychoactive component is delta-9-tetrahydrocannabinol (THC), one of over 100 phytocannabinoid compounds produced by the cannabis plant. THC is the primary compound that drives cannabis abuse potential and is also used and prescribed medically for therapeutic qualities. Despite its therapeutic potential, a significant subpopulation of frequent cannabis or THC users will develop a drug use syndrome termed cannabis use disorder. Individuals suffering from cannabis use disorder exhibit many of the hallmarks of classical addictions including cravings, tolerance, and withdrawal symptoms. Currently, there are no efficacious treatments for cannabis use disorder or withdrawal symptoms. This makes both clinical and preclinical research on the neurobiological mechanisms of these syndromes ever more pertinent. Indeed, basic research using animal models has provided valuable evidence of the neural molecular and cellular actions of cannabis that mediate its behavioral effects. One of the main components being central action on the cannabinoid type-one receptor and downstream intracellular signaling related to the endogenous cannabinoid system. Back-translational studies have provided insight linking preclinical basic and behavioral biology research to better understand symptoms observed at the clinical level. This narrative review aims to summarize major research elucidating the molecular, cellular, and behavioral manifestations of cannabis/THC use that play a role in cannabis use disorder and withdrawal.
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Affiliation(s)
- Andrew J. Kesner
- Laboratory for Integrative NeuroscienceNational Institute on Alcohol Abuse and AlcoholismCenter on Compulsive BehaviorsNational Institutes of HealthBethesdaMDUSA
| | - David M. Lovinger
- Laboratory for Integrative NeuroscienceNational Institute on Alcohol Abuse and AlcoholismCenter on Compulsive BehaviorsNational Institutes of HealthBethesdaMDUSA
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3
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Dvorakova M, Kubik-Zahorodna A, Straiker A, Sedlacek R, Hajkova A, Mackie K, Blahos J. SGIP1 is involved in regulation of emotionality, mood, and nociception and modulates in vivo signalling of cannabinoid CB 1 receptors. Br J Pharmacol 2021; 178:1588-1604. [PMID: 33491188 PMCID: PMC8795748 DOI: 10.1111/bph.15383] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 12/06/2020] [Accepted: 01/09/2021] [Indexed: 01/04/2023] Open
Abstract
Background and Purpose Src homology 3‐domain growth factor receptor‐bound 2‐like endophilin interacting protein 1 (SGIP1) interacts with cannabinoid CB1 receptors. SGIP1 is abundantly and principally expressed within the nervous system. SGIP1 and CB1 receptors co‐localize in axons and presynaptic boutons. SGIP1 interferes with the internalization of activated CB1 receptors in transfected heterologous cells. Consequently, the transient association of CB1 receptors with β‐arrestin2 is enhanced and prolonged, and CB1 receptor‐mediated ERK1/2 signalling is decreased. Because of these actions, SGIP1 may modulate affect, anxiety, pain processing, and other physiological processes controlled by the endocannabinoid system (ECS). Experimental Approach Using a battery of behavioural tests, we investigated the consequences of SGIP1 deletion in tasks regulated by the ECS in SGIP1 constitutive knockout (SGIP1−/−) mice. Key Results In SGIP1−/− mice, sensorimotor gating, exploratory levels, and working memory are unaltered. SGIP1−/− mice have decreased anxiety‐like behaviours. Fear extinction to tone is facilitated in SGIP1−/− females. Several cannabinoid tetrad behaviours are altered in the absence of SGIP1. SGIP1−/− males exhibit abnormal behaviours on Δ9‐tetrahydrocannabinol withdrawal. SGIP1 deletion also reduces acute nociception, and SGIP1−/− mice are more sensitive to analgesics. Conclusion and Implications SGIP1 was detected as a novel protein associated with CB1 receptors, and profoundly modified CB1 receptor signalling. Genetic deletion of SGIP1 particularly affected behavioural tests of mood‐related assessment and the cannabinoid tetrad. SGIP1−/− mice exhibit decreased nociception and augmented responses to CB1 receptor agonists and morphine. These in vivo findings suggest that SGIP1 is a novel modulator of CB1 receptor‐mediated behaviour.
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Affiliation(s)
- Michaela Dvorakova
- Department of Molecular Pharmacology, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague 4, Czech Republic.,Department of Psychological and Brain Sciences, Gill Center for Molecular Bioscience, Indiana University, Bloomington, Indiana, USA
| | - Agnieszka Kubik-Zahorodna
- The Czech Center for Phenogenomics, Institute of Molecular Genetics of the Czech Academy of Sciences, Vestec, Czech Republic
| | - Alex Straiker
- Department of Psychological and Brain Sciences, Gill Center for Molecular Bioscience, Indiana University, Bloomington, Indiana, USA
| | - Radislav Sedlacek
- The Czech Center for Phenogenomics, Institute of Molecular Genetics of the Czech Academy of Sciences, Vestec, Czech Republic
| | - Alena Hajkova
- Department of Molecular Pharmacology, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague 4, Czech Republic
| | - Ken Mackie
- Department of Psychological and Brain Sciences, Gill Center for Molecular Bioscience, Indiana University, Bloomington, Indiana, USA
| | - Jaroslav Blahos
- Department of Molecular Pharmacology, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague 4, Czech Republic
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Chen CC, Chang C, Hsu YH, Peng YJ, Lee HS, Huang GS. fMRI indicates cortical activation through TRPV1 modulation during acute gouty attacks. Sci Rep 2019; 9:12348. [PMID: 31451732 PMCID: PMC6710282 DOI: 10.1038/s41598-019-48656-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Accepted: 08/07/2019] [Indexed: 11/09/2022] Open
Abstract
Gout is one of the most painful disease conditions. The central mechanism of pain processing in this condition remains elusive. Cerebral blood volume (CBV) responses are faithful correlates of brain activity changes; the application of CBV-weighted functional magnetic resonance imaging (fMRI) may shed light on the issue of interest. Transient receptor potential vanilloid 1 (TRPV1) is a critical ion channel expressed both peripherally in nociceptors and centrally in the brain. Whether TRPV1 plays a critical role in gout pain was also explored. Results showed that, in rats with gouty arthritis, noxious stimulation induced CBV increases in the primary somatosensory cortex and thalamus. These increases were correlated with up-regulated TRPV1 protein expression and pain behavior. Selective blockage of central TRPV1 channel activity by intrathecal administration of AMG9810 reversed the induced pain, and abolished the induced CBV increase in thalamocortical regions. The findings support that TRPV1 activation in the central pain pathway is crucial to the augmentation of pain in gouty conditions. This new information supports the development of TRPV1-based drugs for treating gout pain, while fMRI can be useful for repeated evaluation of brain activity changes induced by gout.
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Affiliation(s)
- Chiao-Chi Chen
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Chen Chang
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan.
| | - Yi-Hua Hsu
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Yi-Jen Peng
- Department of Pathology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Herng-Sheng Lee
- Department of Pathology and Laboratory Medicine, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan
| | - Guo-Shu Huang
- Department of Radiology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan. .,Department of Medical Research, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
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Yang Y, Kreko-Pierce T, Howell R, Pugh JR. Long-term depression of presynaptic cannabinoid receptor function at parallel fibre synapses. J Physiol 2019; 597:3167-3181. [PMID: 31020998 DOI: 10.1113/jp277727] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 04/18/2019] [Indexed: 12/22/2022] Open
Abstract
KEY POINTS Inhibition of synaptic responses by activation of presynaptic cannabinoid type-1 (Cb1) receptors is reduced at parallel fibre synapses in the cerebellum following 4 Hz stimulation. Activation of adenylyl cyclase is necessary and sufficient for down-regulation of Cb1 receptors induced by 4 Hz stimulation. 4 Hz stimulation reduces Cb1 receptor function by (i) increasing the rate of endocannabinoid clearance from the synapse and (ii) decreasing expression of Cb1 receptors. ABSTRACT Cannabinoid type-1 receptors (Cb1R) are expressed in the presynaptic membrane of many synapses, including parallel fibre-Purkinje cell synapses in the cerebellum, where they are involved in short- and long-term plasticity of synaptic responses. We show that Cb1R expression itself is a plastic property of the synapse regulated by physiological activity patterns. We made patch clamp recordings from Purkinje cells in cerebellar slices and assessed Cb1R activity by measuring depolarization-induced suppression of excitation (DSE). We find that DSE is normally stable at parallel fibre synapses but, following 4 Hz stimulation, DSE is persistently reduced and recovers more rapidly. Using a combination of electrophysiology, pharmacology and biochemistry, we show that changes in DSE are a result of the reduced expression of Cb1Rs and increased degradation of endocannabinoids by monoacylglycerol lipase. Long-term changes in presynaptic Cb1R expression may alter other forms of Cb1R-dependent plasticity at parallel fibre synapses, priming or inhibiting the circuit for associative learning.
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Affiliation(s)
- Ying Yang
- University of Texas Health Science Center at San Antonio, Department of Cellular and Integrative Physiology, San Antonio, TX, USA.,Xiangya School of Medicine, Department of Pain, The Third Xiangya Hospital and Institute of Pain Medicine, Central South University, Changsha, Hunan Province, China
| | - Tabita Kreko-Pierce
- University of Texas Health Science Center at San Antonio, Department of Cellular and Integrative Physiology, San Antonio, TX, USA
| | - Rebecca Howell
- University of Texas Health Science Center at San Antonio, Department of Cellular and Integrative Physiology, San Antonio, TX, USA.,Present address: Oklahoma Medical Research Foundation & University of Oklahoma Health Science Center, Oklahoma City, OK, USA
| | - Jason R Pugh
- University of Texas Health Science Center at San Antonio, Department of Cellular and Integrative Physiology, San Antonio, TX, USA.,Center for Biomedical Neuroscience, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
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Thakre PP, Bellingham MC. Capsaicin causes robust reduction in glycinergic transmission to rat hypoglossal motor neurons via a TRPV1-independent mechanism. J Neurophysiol 2019; 121:1535-1542. [PMID: 30785813 DOI: 10.1152/jn.00059.2019] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The effect of capsaicin on glycinergic synaptic transmission to juvenile rat hypoglossal motor neurons in acute brainstem slices was evaluated in the presence of TTX. Capsaicin caused a robust decrease in miniature IPSC frequency, amplitude, and half-width, showing that this effect is independent of action potential generation. In the presence of capsazepine, a classic TRPV1 antagonist, capsaicin was still able to reduce spontaneous inhibitory postsynaptic current (IPSC) amplitude and frequency. We further investigated whether the effect of capsaicin on glycinergic transmission to hypoglossal motor neurons is pre- or postsynaptic in nature by recording pairs of evoked IPSCs. Interestingly, capsaicin also reduced evoked IPSC amplitude without affecting paired-pulse ratio, indicating a postsynaptic mechanism of action. Significant reduction was also observed in evoked IPSC half-width, rise time, and decay tau. We also show that capsaicin does not have any effect on either transient (It) or sustained (Is) potassium currents. Finally, we also show that the hyperpolarization-activated cationic current (Ih) also remains unchanged after capsaicin application. NEW & NOTEWORTHY Capsaicin reduces the amplitude of quantal and evoked glycinergic inhibitory neurotransmission to brainstem motor neurons without altering activity-dependent transmitter release. This effect of capsaicin is not due to activation of TRPV1 receptors, as it is not blocked by capsazepine, a TRPV1 receptor antagonist. Capsaicin does not alter voltage-dependent potassium current or the hyperpolarization-activated cationic current in brainstem motor neurons.
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Affiliation(s)
- Prajwal P Thakre
- Faculty of Medicine, School of Biomedical Sciences, University of Queensland , Brisbane, Queensland , Australia
| | - Mark C Bellingham
- Faculty of Medicine, School of Biomedical Sciences, University of Queensland , Brisbane, Queensland , Australia
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7
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Cleeren E, Casteels C, Goffin K, Koole M, Van Laere K, Janssen P, Van Paesschen W. Positron emission tomography imaging of cerebral glucose metabolism and type 1 cannabinoid receptor availability during temporal lobe epileptogenesis in the amygdala kindling model in rhesus monkeys. Epilepsia 2018; 59:959-970. [DOI: 10.1111/epi.14059] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/22/2018] [Indexed: 01/31/2023]
Affiliation(s)
- Evy Cleeren
- Laboratory for Neuro‐ and Psychophysiology KU Leuven Leuven Belgium
- Laboratory for Epilepsy Research KU Leuven Leuven Belgium
| | - Cindy Casteels
- Nuclear Medicine & Molecular Imaging Department of Imaging and Pathology KU Leuven Leuven Belgium
- Molecular Small Animal Imaging Center (MoSAIC) KU Leuven Leuven Belgium
| | - Karolien Goffin
- Nuclear Medicine & Molecular Imaging Department of Imaging and Pathology KU Leuven Leuven Belgium
- Molecular Small Animal Imaging Center (MoSAIC) KU Leuven Leuven Belgium
| | - Michel Koole
- Nuclear Medicine & Molecular Imaging Department of Imaging and Pathology KU Leuven Leuven Belgium
- Molecular Small Animal Imaging Center (MoSAIC) KU Leuven Leuven Belgium
| | - Koen Van Laere
- Nuclear Medicine & Molecular Imaging Department of Imaging and Pathology KU Leuven Leuven Belgium
- Molecular Small Animal Imaging Center (MoSAIC) KU Leuven Leuven Belgium
| | - Peter Janssen
- Laboratory for Neuro‐ and Psychophysiology KU Leuven Leuven Belgium
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8
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Thakre PP, Bellingham MC. Capsaicin Enhances Glutamatergic Synaptic Transmission to Neonatal Rat Hypoglossal Motor Neurons via a TRPV1-Independent Mechanism. Front Cell Neurosci 2017; 11:383. [PMID: 29259542 PMCID: PMC5723349 DOI: 10.3389/fncel.2017.00383] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 11/17/2017] [Indexed: 01/02/2023] Open
Abstract
We investigated whether capsaicin modulated synaptic transmission to hypoglossal motor neurons (HMNs) by acting on transient receptor potential vanilloid type 1 (TRPV1) receptors. Using whole-cell patch clamp recording from neonatal rat HMNs, we found that capsaicin increased spontaneous excitatory post-synaptic current (sEPSC) frequency and amplitude. Interestingly, the only effect of capsaicin on spontaneous inhibitory post-synaptic currents (sIPSCs) was a significant decrease in sIPSC amplitude without altering frequency, indicating a post-synaptic mechanism of action. The frequency of miniature excitatory post-synaptic currents (mEPSCs), recorded in the presence of tetrodotoxin (TTX), was also increased by capsaicin, but capsaicin did not alter mEPSC amplitude, consistent with a pre-synaptic mechanism of action. A negative shift in membrane current (Iholding) was elicited by capsaicin under both recording conditions. The effect of capsaicin on excitatory synaptic transmission remained unchanged in the presence of the TRPV1 antagonists, capsazepine or SB366791, suggesting that capsaicin acts to modulate EPSCs via a mechanism which does not require TRPV1 activation. Capsaicin, however, did not alter evoked excitatory post-synaptic currents (eEPSCs) or the paired-pulse ratio (PPR) of eEPSCs. Repetitive action potential (AP) firing in HMNs was also unaltered by capsaicin, indicating that capsaicin does not change HMN intrinsic excitability. We have demonstrated that capsaicin modulates glutamatergic excitatory, as well as glycinergic inhibitory, synaptic transmission in HMNs by differing pre- and post-synaptic mechanisms. These results expand our understanding regarding the extent to which capsaicin can modulate synaptic transmission to central neurons.
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Affiliation(s)
- Prajwal P Thakre
- Faculty of Medicine, School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia
| | - Mark C Bellingham
- Faculty of Medicine, School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia
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9
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Jia YF, Li YC, Tang YP, Cao J, Wang LP, Yang YX, Xu L, Mao RR. Interference of TRPV1 function altered the susceptibility of PTZ-induced seizures. Front Cell Neurosci 2015; 9:20. [PMID: 25713512 PMCID: PMC4322730 DOI: 10.3389/fncel.2015.00020] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Accepted: 01/13/2015] [Indexed: 01/21/2023] Open
Abstract
Transient receptor potential vanilloid 1 (TRPV1) is widely distributed in the central nervous system (CNS) including hippocampus, and regulates the balance of excitation and inhibition in CNS, which imply its important role in epilepsy. We used both pharmacological manipulations and transgenic mice to disturb the function of TRPV1 and then studied the effects of these alterations on the susceptibility of pentylenetetrazol (PTZ)-induced seizures. Our results showed that systemic administration of TRPV1 agonist capsaicin (CAP, 40 mg/kg) directly induced tonic-clonic seizures (TCS) without PTZ induction. The severity of seizure was increased in lower doses of CAP groups (5 and 10 mg/kg), although the latency to TCS was delayed. On the other hand, systemic administration of TRPV1 antagonist capsazepine (CPZ, 0.05 and 0.5 mg/kg) and TRPV1 knockout mice exhibited delayed latency to TCS and reduced mortality. Furthermore, hippocampal administration of CPZ (10 and 33 nmol/μL/side) was firstly reported to increase the latency to TCS, decrease the maximal grade of seizure and mortality. It is worth noting that decreased susceptibility of PTZ-induced seizures was observed in hippocampal TRPV1 overexpression mice and hippocampal CAP administration (33 nmol/μL/side), which is opposite from results of systemic agonist CAP. Our findings suggest that the systemic administration of TRPV1 antagonist may be a novel therapeutic target for epilepsy, and alteration of hippocampal TRPV1 function exerts a critical role in seizure susceptibility.
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Affiliation(s)
- Yun-Fang Jia
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, and KIZ/CUHK Joint Laboratory of Bioresources and Molecular Research in Common Disease, and Laboratory of Learning and Memory, Kunming Institute of Zoology, Chinese Academy of Sciences Yunnan, China ; Kunming College of Life Science, University of Chinese Academy of Sciences Beijing, China
| | - Ying-Chao Li
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, and KIZ/CUHK Joint Laboratory of Bioresources and Molecular Research in Common Disease, and Laboratory of Learning and Memory, Kunming Institute of Zoology, Chinese Academy of Sciences Yunnan, China ; School of Life Sciences, University of Science and Technology of China Hefei, China
| | - Yan-Ping Tang
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, and KIZ/CUHK Joint Laboratory of Bioresources and Molecular Research in Common Disease, and Laboratory of Learning and Memory, Kunming Institute of Zoology, Chinese Academy of Sciences Yunnan, China ; Kunming College of Life Science, University of Chinese Academy of Sciences Beijing, China
| | - Jun Cao
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, and KIZ/CUHK Joint Laboratory of Bioresources and Molecular Research in Common Disease, and Laboratory of Learning and Memory, Kunming Institute of Zoology, Chinese Academy of Sciences Yunnan, China ; Kunming College of Life Science, University of Chinese Academy of Sciences Beijing, China
| | - Li-Ping Wang
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, and KIZ/CUHK Joint Laboratory of Bioresources and Molecular Research in Common Disease, and Laboratory of Learning and Memory, Kunming Institute of Zoology, Chinese Academy of Sciences Yunnan, China ; Kunming College of Life Science, University of Chinese Academy of Sciences Beijing, China
| | - Yue-Xiong Yang
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, and KIZ/CUHK Joint Laboratory of Bioresources and Molecular Research in Common Disease, and Laboratory of Learning and Memory, Kunming Institute of Zoology, Chinese Academy of Sciences Yunnan, China ; Kunming College of Life Science, University of Chinese Academy of Sciences Beijing, China
| | - Lin Xu
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, and KIZ/CUHK Joint Laboratory of Bioresources and Molecular Research in Common Disease, and Laboratory of Learning and Memory, Kunming Institute of Zoology, Chinese Academy of Sciences Yunnan, China ; Kunming College of Life Science, University of Chinese Academy of Sciences Beijing, China
| | - Rong-Rong Mao
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, and KIZ/CUHK Joint Laboratory of Bioresources and Molecular Research in Common Disease, and Laboratory of Learning and Memory, Kunming Institute of Zoology, Chinese Academy of Sciences Yunnan, China ; Kunming College of Life Science, University of Chinese Academy of Sciences Beijing, China
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10
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Martins D, Tavares I, Morgado C. "Hotheaded": the role OF TRPV1 in brain functions. Neuropharmacology 2014; 85:151-7. [PMID: 24887171 DOI: 10.1016/j.neuropharm.2014.05.034] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Revised: 05/12/2014] [Accepted: 05/20/2014] [Indexed: 12/24/2022]
Abstract
The TRPV1 (vanilloid 1) channel is best known for its role in sensory transmission in the nociceptive neurons of the peripheral nervous system. Although first studied in the dorsal root ganglia as the receptor for capsaicin, TRPV1 has been recently recognized to have a broader distribution in the central nervous system, where it is likely to constitute an atypical neurotransmission system involved in several functions through modulation of both neuronal and glial activities. The endovanilloid-activated brain TRPV1 channels seem to be involved in somatosensory, motor and visceral functions. Recent studies suggested that TRPV1 channels also account for more complex functions, as addiction, anxiety, mood and cognition/learning. However, more studies are needed before the relevance of TRPV1 in brain activity can be clearly stated. This review highlights the increasing importance of TRPV1 as a regulator of brain function and discusses possible bases for the future development of new therapeutic approaches that by targeting brain TRPV1 receptors might be used for the treatment of several neurological disorders.
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Affiliation(s)
- D Martins
- Departamento de Biologia Experimental, Faculdade de Medicina, Universidade do Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Portugal
| | - I Tavares
- Departamento de Biologia Experimental, Faculdade de Medicina, Universidade do Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Portugal
| | - C Morgado
- Departamento de Biologia Experimental, Faculdade de Medicina, Universidade do Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Portugal.
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11
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Köles L, Garção P, Zádori ZS, Ferreira SG, Pinheiro BS, da Silva-Santos CS, Ledent C, Köfalvi A. Presynaptic TRPV1 vanilloid receptor function is age- but not CB1 cannabinoid receptor-dependent in the rodent forebrain. Brain Res Bull 2013; 97:126-35. [PMID: 23831917 DOI: 10.1016/j.brainresbull.2013.06.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2012] [Revised: 06/14/2013] [Accepted: 06/27/2013] [Indexed: 02/01/2023]
Abstract
Neocortical and striatal TRPV1 (vanilloid or capsaicin) receptors (TRPV1Rs) are excitatory ligand-gated ion channels, and are implicated in psychiatric disorders. However, the purported presynaptic neuromodulator role of TRPV1Rs in glutamatergic, serotonergic or dopaminergic terminals of the rodent forebrain remains little understood. With the help of patch-clamp electrophysiology and neurochemical approaches, we mapped the age-dependence of presynaptic TRPV1R function, and furthermore, we aimed at exploring whether the presence of CB1 cannabinoid receptors (CB1Rs) influences the function of the TRPV1Rs, as both receptor types share endogenous ligands. We found that the major factor which affects presynaptic TRPV1R function is age: by post-natal day 13, the amplitude of capsaicin-induced release of dopamine and glutamate is halved in the rat striatum, and two weeks later, capsaicin already loses its effect. However, TRPV1R receptor function is not enhanced by chemical or genetic ablation of the CB1Rs in dopaminergic, glutamatergic and serotonergic terminals of the mouse brain. Altogether, our data indicate a possible neurodevelopmental role for presynaptic TRPV1Rs in the rodent brain, but we found no cross-talk between TRPV1Rs and CB1Rs in the same nerve terminal.
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Key Words
- 3Rs
- 4-AP
- 4-aminopyridine
- 7-, 14-, 29- and 60-day-old
- 7D, 14D, 29D, 60D
- ACEA
- ARC
- ARRIVE
- AUC
- American Radiolabeled Chemicals
- Animal Research: Reporting In Vivo Experiments
- BCA
- BSA
- CB(1) cannabinoid receptor
- CB(1)R
- DMSO
- DPM
- DTT
- Dopamine
- ECF
- EDTA
- EGTA
- FR%
- Federation for Laboratory Animal Science Associations
- Felasa
- GABA
- Glutamate
- HEPES
- KHR
- KO
- Krebs-HEPES-Ringer
- LiGTP
- MAO B
- MgATP
- N-(2-hydroxyethyl)piperazine-N′-(2-ethanesulfonic acid)
- N-arachidonyl dopamine
- NADA
- NO
- PMSF
- PVDF
- RTX
- SDS
- SEM
- Serotonin
- Striatum
- TBS-T
- TRPV(1) vanilloid receptor
- TRPV(1)R and TRPV(4)R
- Tris
- Tris-buffered saline with Tween 20
- WT
- aCSF
- arachidonyl-2′-chloroethylamide
- area-under-the-curve
- artificial cerebrospinal fluid
- bicinchoninic acid
- bovine serum albumin
- cannabinoid receptor type 1
- dimethyl sulfoxide
- disintegration per minute
- dithiothreitol
- enhanced chemi-fluorescence
- ethylene glycol-bis(2-aminoethylether)-N,N,N′,N′-tetraacetic acid
- ethylenediaminetetraacetic acid
- fractional release %
- knockout
- lithium guanozine triphosphate
- magnesium adenosine triphosphate
- monoamine oxidase B
- nitric oxide
- phenylmethanesulfonyl fluoride
- polyvinylidene difluoride
- replacement, reduction, refinement
- resiniferatoxin
- sEPSCs
- sodium dodecyl sulfate
- spontaneous excitatory postsynaptic currents
- standard error of the mean
- transient release potential receptor vanilloid type 4
- tris(hydroxymethyl)aminomethane
- wild-type
- γ-aminobutyric acid
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Affiliation(s)
- László Köles
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, Semmelweis University, Nagyvárad tér 4, 1089 Budapest, Hungary
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12
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Identification of mRNA for endocannabinoid biosynthetic enzymes within hippocampal pyramidal cells and CA1 stratum radiatum interneuron subtypes using quantitative real-time polymerase chain reaction. Neuroscience 2012; 218:89-99. [PMID: 22609938 DOI: 10.1016/j.neuroscience.2012.05.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2012] [Revised: 05/03/2012] [Accepted: 05/05/2012] [Indexed: 11/22/2022]
Abstract
The hippocampus is required for short-term memory and contains both excitatory pyramidal cells and inhibitory interneurons. These cells exhibit various forms of synaptic plasticity, the mechanism underlying learning and memory. More recently, endocannabinoids were identified to be involved in synaptic plasticity. Our goal was to describe the distribution of endocannabinoid biosynthetic enzymes within CA1 stratum radiatum interneurons and CA3/CA1 pyramidal cells. We extracted mRNA from single interneurons and pyramidal cells and used real-time quantitative polymerase chain reaction (RT-PCR) to detect the presence of 12-lipoxygenase, N-acyl-phosphatidylethanolamine-specific phospholipase D, diacylglycerol lipase α, and type I metabotropic glutamate receptors, all known to be involved in endocannabinoid production and plasticity. We observed that the expression of endocannabinoid biosynthetic enzyme mRNA does occur within interneurons and that it is coexpressed with type I metabotropic glutamate receptors, suggesting interneurons have the potential to produce endocannabinoids. We also identified that CA3 and CA1 pyramidal cells express endocannabinoid biosynthetic enzyme mRNA. Our data provide the first molecular biological evidence for putative endocannabinoid production in interneurons, suggesting their potential ability to regulate endocannabinoid-mediated processes, such as synaptic plasticity.
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13
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Andó RD, Bíró J, Csölle C, Ledent C, Sperlágh B. The inhibitory action of exo- and endocannabinoids on [³H]GABA release are mediated by both CB₁and CB₂receptors in the mouse hippocampus. Neurochem Int 2011; 60:145-52. [PMID: 22133429 DOI: 10.1016/j.neuint.2011.11.012] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2011] [Revised: 10/19/2011] [Accepted: 11/15/2011] [Indexed: 11/15/2022]
Abstract
Exogenous and endogenous cannabinoids play an important role in modulating the release of neurotransmitters in hippocampal excitatory and inhibitory networks, thus having profound effect on higher cognitive and emotional functions such as learning and memory. In this study we have studied the effect of cannabinoid agonists on the potassium depolarization-evoked [(3)H]GABA release from hippocampal synaptosomes in the wild-type (WT) and cannabinoid 1 receptor (CB(1)R)-null mutant mice. All tested cannabinoid agonists (WIN55,212-2, CP55,940, HU-210, 2-arachidonoyl-glycerol, 2-AG; delta-9-tetra-hydrocannabinol, THC) inhibited [(3)H]GABA release in WT mice with the following rank order of agonist potency: HU-210>CP55,490>WIN55,212-2>>2-AG>THC. By contrast, 2-AG and THC displayed the greatest efficacy eliciting almost complete inhibition of evoked [(3)H]GABA efflux, whereas the maximal inhibition obtained by HU-210, CP55,490, and WIN55,212-2 were less, eliciting not more than 40% inhibition. The inhibitory effect of WIN55,212-2, THC and 2-AG on evoked [(3)H]GABA efflux was antagonized by the CB(1) receptor inverse agonist AM251 (0.5 μM) in the WT mice. In the CB(1)R knockout mice the inhibitory effects of all three agonists were attenuated. In these mice, AM251 did not antagonize, but further reduced the [(3)H]GABA release in the presence of the synthetic agonist WIN55,212-2. By contrast, the concentration-dependent inhibitory effects of THC and 2-AG were partially antagonized by AM251 in the absence of CB(1) receptors. Finally, the inhibition of evoked [(3)H]GABA efflux by THC and 2-AG was also partially attenuated by AM630 (1 μM), the CB(2) receptor-selective antagonist, both in WT and CB(1) knockout mice. Our data prove the involvement of CB(1) receptors in the effect of exo- and endocannabinoids on GABA efflux from hippocampal nerve terminals. In addition, in the effect of the exocannabinoid THC and the endocannabinoid 2-AG, non-CB(1), probably CB(2)-like receptors are also involved.
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MESH Headings
- Animals
- Cannabinoid Receptor Modulators/physiology
- Cannabinoids/pharmacology
- Endocannabinoids
- Hippocampus/metabolism
- Hippocampus/physiology
- Male
- Mice
- Mice, Inbred Strains
- Mice, Knockout
- Neural Inhibition/genetics
- Neural Inhibition/physiology
- Presynaptic Terminals/metabolism
- Presynaptic Terminals/physiology
- Receptor, Cannabinoid, CB1/deficiency
- Receptor, Cannabinoid, CB1/genetics
- Receptor, Cannabinoid, CB1/metabolism
- Receptor, Cannabinoid, CB2/genetics
- Receptor, Cannabinoid, CB2/metabolism
- Tritium
- gamma-Aminobutyric Acid/metabolism
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Affiliation(s)
- Rómeó D Andó
- Laboratory of Molecular Pharmacology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
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14
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Bennion D, Jensen T, Walther C, Hamblin J, Wallmann A, Couch J, Blickenstaff J, Castle M, Dean L, Beckstead S, Merrill C, Muir C, St. Pierre T, Williams B, Daniel S, Edwards JG. Transient receptor potential vanilloid 1 agonists modulate hippocampal CA1 LTP via the GABAergic system. Neuropharmacology 2011; 61:730-8. [DOI: 10.1016/j.neuropharm.2011.05.018] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2011] [Revised: 05/07/2011] [Accepted: 05/17/2011] [Indexed: 10/18/2022]
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15
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Sidhpura N, Parsons LH. Endocannabinoid-mediated synaptic plasticity and addiction-related behavior. Neuropharmacology 2011; 61:1070-87. [PMID: 21669214 DOI: 10.1016/j.neuropharm.2011.05.034] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2011] [Revised: 05/26/2011] [Accepted: 05/29/2011] [Indexed: 01/20/2023]
Abstract
Endogenous cannabinoids (eCBs) are retrograde messengers that provide feedback inhibition of both excitatory and inhibitory transmission in brain through the activation of presynaptic CB₁ receptors. Substantial evidence indicates that eCBs mediate various forms of short- and long-term plasticity in brain regions involved in the etiology of addiction. The present review provides an overview of the mechanisms through which eCBs mediate various forms of synaptic plasticity and discusses evidence that eCB-mediated plasticity is disrupted following exposure to a variety of abused substances that differ substantially in pharmacodynamic mechanism including alcohol, psychostimulants and cannabinoids. The possible involvement of dysregulated eCB signaling in maladaptive behaviors that evolve over long-term drug exposure is also discussed, with a particular focus on altered behavioral responses to drug exposure, deficient extinction of drug-related memories, increased drug craving and relapse, heightened stress sensitivity and persistent affective disruption (anxiety and depression).
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Affiliation(s)
- Nimish Sidhpura
- Committee on the Neurobiology of Addictive Disorders, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, CA 92037, USA
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16
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Trpv1 reporter mice reveal highly restricted brain distribution and functional expression in arteriolar smooth muscle cells. J Neurosci 2011; 31:5067-77. [PMID: 21451044 DOI: 10.1523/jneurosci.6451-10.2011] [Citation(s) in RCA: 384] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The heat and capsaicin receptor, TRPV1, is required for the detection of painful heat by primary afferent pain fibers (nociceptors), but the extent to which functional TRPV1 channels are expressed in the CNS is debated. Because previous evidence is based primarily on indirect physiological responses to capsaicin, here we genetically modified the Trpv1 locus to reveal, with excellent sensitivity and specificity, the distribution of TRPV1 in all neuronal and non-neuronal tissues. In contrast to reports of widespread and robust expression in the CNS, we find that neuronal TRPV1 is primarily restricted to nociceptors in primary sensory ganglia, with minimal expression in a few discrete brain regions, most notably in a contiguous band of cells within and adjacent to the caudal hypothalamus. We confirm hypothalamic expression in the mouse using several complementary approaches, including in situ hybridization, calcium imaging, and electrophysiological recordings. Additional in situ hybridization experiments in rat, monkey, and human brain demonstrate that the restricted expression of TRPV1 in the CNS is conserved across species. Outside of the CNS, we find TRPV1 expression in a subset of arteriolar smooth muscle cells within thermoregulatory tissues. Here, capsaicin increases calcium uptake and induces vasoconstriction, an effect that likely counteracts the vasodilation produced by activation of neuronal TRPV1.
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17
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Zschenderlein C, Gebhardt C, von Bohlen und Halbach O, Kulisch C, Albrecht D. Capsaicin-induced changes in LTP in the lateral amygdala are mediated by TRPV1. PLoS One 2011; 6:e16116. [PMID: 21249195 PMCID: PMC3020947 DOI: 10.1371/journal.pone.0016116] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2010] [Accepted: 12/14/2010] [Indexed: 01/15/2023] Open
Abstract
The transient receptor potential vanilloid type 1 (TRPV1) channel is a well recognized polymodal signal detector that is activated by painful stimuli such as capsaicin. Here, we show that TRPV1 is expressed in the lateral nucleus of the amygdala (LA). Despite the fact that the central amygdala displays the highest neuronal density, the highest density of TRPV1 labeled neurons was found within the nuclei of the basolateral complex of the amygdala. Capsaicin specifically changed the magnitude of long-term potentiation (LTP) in the LA in brain slices of mice depending on the anesthetic (ether, isoflurane) used before euthanasia. After ether anesthesia, capsaicin had a suppressive effect on LA-LTP both in patch clamp and in extracellular recordings. The capsaicin-induced reduction of LTP was completely blocked by the nitric oxide synthase (NOS) inhibitor L-NAME and was absent in neuronal NOS as well as in TRPV1 deficient mice. The specific antagonist of cannabinoid receptor type 1 (CB1), AM 251, was also able to reduce the inhibitory effect of capsaicin on LA-LTP, suggesting that stimulation of TRPV1 provokes the generation of anandamide in the brain which seems to inhibit NO synthesis. After isoflurane anesthesia before euthanasia capsaicin caused a TRPV1-mediated increase in the magnitude of LA-LTP. Therefore, our results also indicate that the appropriate choice of the anesthetics used is an important consideration when brain plasticity and the action of endovanilloids will be evaluated. In summary, our results demonstrate that TRPV1 may be involved in the amygdala control of learning mechanisms.
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Affiliation(s)
- Carsten Zschenderlein
- Institute of Neurophysiology, Charité - Universitätsmedizin Berlin, CVK, Berlin, Germany
| | - Christine Gebhardt
- Institute of Neurophysiology, Charité - Universitätsmedizin Berlin, CVK, Berlin, Germany
| | | | - Christoph Kulisch
- Institute of Neurophysiology, Charité - Universitätsmedizin Berlin, CVK, Berlin, Germany
| | - Doris Albrecht
- Institute of Neurophysiology, Charité - Universitätsmedizin Berlin, CVK, Berlin, Germany
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18
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Premkumar LS, Sikand P. TRPV1: a target for next generation analgesics. Curr Neuropharmacol 2010; 6:151-63. [PMID: 19305794 PMCID: PMC2647151 DOI: 10.2174/157015908784533888] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2007] [Revised: 10/17/2007] [Accepted: 11/11/2007] [Indexed: 12/11/2022] Open
Abstract
Transient Receptor Potential Vanilloid 1 (TRPV1) is a Ca2+ permeant non-selective cation channel expressed in a subpopulation of primary afferent neurons. TRPV1 is activated by physical and chemical stimuli. It is critical for the detection of nociceptive and thermal inflammatory pain as revealed by the deletion of the TRPV1 gene. TRPV1 is distributed in the peripheral and central terminals of the sensory neurons and plays a role in initiating action potentials at the nerve terminals and modulating neurotransmitter release at the first sensory synapse, respectively. Distribution of TRPV1 in the nerve terminals innervating blood vessels and in parts of the CNS that are not subjected to temperature range that is required to activate TRPV1 suggests a role beyond a noxious thermal sensor. Presently, TRPV1 is being considered as a target for analgesics through evaluation of different antagonists. Here, we will discuss the distribution and the functions of TRPV1, potential use of its agonists and antagonists as analgesics and highlight the functions that are not related to nociceptive transmission that might lead to adverse effects.
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Affiliation(s)
- Louis S Premkumar
- Department of Pharmacology, Southern Illinois University School of Medicine Springfield, IL 62702, USA.
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19
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Bhaskaran MD, Smith BN. Effects of TRPV1 activation on synaptic excitation in the dentate gyrus of a mouse model of temporal lobe epilepsy. Exp Neurol 2010; 223:529-36. [PMID: 20144892 DOI: 10.1016/j.expneurol.2010.01.021] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2009] [Revised: 01/08/2010] [Accepted: 01/31/2010] [Indexed: 11/25/2022]
Abstract
Temporal lobe epilepsy (TLE) is a condition characterized by an imbalance between excitation and inhibition in the temporal lobe. Hallmarks of this change are axon sprouting and accompanying synaptic reorganization in the temporal lobe. Synthetic and endogenous cannabinoids have variable therapeutic potential in treating intractable temporal lobe epilepsy, in part because cannabinoid ligands can bind multiple receptor types. This study utilized in vitro electrophysiological methods to examine the effect of transient receptor potential vanilloid type 1 (TRPV1) activation in dentate gyrus granule cells in a murine model of TLE. Capsaicin, a selective TRPV1 agonist had no measurable effect on overall synaptic input to granule cells in control animals, but significantly enhanced spontaneous and miniature EPSC frequency in mice with TLE. Exogenous application of anandamide, an endogenous cannabinoid that acts at both TRPV1 and cannabinoid type 1 receptors (CB1R), also enhanced glutamate release in the presence of a CB1R antagonist. Anandamide reduced the EPSC frequency when TRPV1 were blocked with capsazepine. Western blot analysis of TRPV1 receptor indicated protein expression was significantly greater in the dentate gyrus of mice with TLE compared with control mice. This study indicates that a prominent cannabinoid agonist can increase excitatory circuit activity in the synaptically reorganized dentate gyrus of mice with TLE by activating TRPV1 receptors, and suggests caution in designing anticonvulsant therapy based on modulating the endocannabinoid system.
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Affiliation(s)
- Muthu D Bhaskaran
- Department of Cell and Molecular Biology, Tulane University, New Orleans, Louisiana 70118, USA
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20
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Gomes I, Grushko JS, Golebiewska U, Hoogendoorn S, Gupta A, Heimann AS, Ferro ES, Scarlata S, Fricker LD, Devi LA. Novel endogenous peptide agonists of cannabinoid receptors. FASEB J 2009; 23:3020-9. [PMID: 19380512 DOI: 10.1096/fj.09-132142] [Citation(s) in RCA: 117] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Hemopressin (Hp), a 9-residue alpha-hemoglobin-derived peptide, was previously reported to function as a CB(1) cannabinoid receptor antagonist (1) . In this study, we report that mass spectrometry (MS) data from peptidomics analyses of mouse brain extracts identified N-terminally extended forms of Hp containing either three (RVD-Hpalpha) or two (VD-Hpalpha) additional amino acids, as well as a beta-hemoglobin-derived peptide with sequence similarity to that of hemopressin (VD-Hpbeta). Characterization of the alpha-hemoglobin-derived peptides using binding and functional assays shows that in contrast to Hp, which functions as a CB(1) cannabinoid receptor antagonist, both RVD-Hpalpha and VD-Hpalpha function as agonists. Studies examining the increase in the phosphorylation of ERK1/2 levels or release of intracellular Ca(2+) indicate that these peptides activate a signal transduction pathway distinct from that activated by the endocannabinoid, 2-arachidonoylglycerol, or the classic CB(1) agonist, Hu-210. This finding suggests an additional mode of regulation of endogenous cannabinoid receptor activity. Taken together, these results suggest that the CB(1) receptor is involved in the integration of signals from both lipid- and peptide-derived signaling molecules.
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Affiliation(s)
- Ivone Gomes
- Department of Pharmacology and Systems Therapeutics, Mt. Sinai School of Medicine, New York, NY 10029, USA
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21
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Ferreira SG, Lomaglio T, Avelino A, Cruz F, Oliveira CR, Cunha RA, Köfalvi A. N-acyldopamines control striatal input terminals via novel ligand-gated cation channels. Neuropharmacology 2008; 56:676-83. [PMID: 19101577 DOI: 10.1016/j.neuropharm.2008.12.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2008] [Revised: 11/20/2008] [Accepted: 12/01/2008] [Indexed: 01/01/2023]
Abstract
Endogenous analogues of capsaicin, N-acyldopamines, were previously identified from striatal extracts, but the putative presynaptic role of their receptor, the TRPV(1)R (formerly: vanilloid or capsaicin receptor) in the caudate-putamen is unclear. We found that the endogenous TRPV(1)R agonists, N-arachidonoyldopamine (NADA) and oleoyldopamine (OLDA) with EC(50) values in the nanomolar range, as well as the synthetic TRPV(1)R activator 2-aminoethoxydiphenylborane (2APB), and palmytoyldopamine (PALDA, another endogenous N-acyldopamine inactive at the TRPV(1)R), but not capsaicin or other endogenous and synthetic cannabinoids, triggered a rapid Ca(2+) entry with the concomitant stimulation of glutamate and dopamine release. These effects persisted in the TRPV(1)R null-mutant mice, and were insensitive to antagonists of common ionotropic receptors, to several TRPV(1)R antagonists and to the absence of K(+). Furthermore, these N-acyldopamine receptors in glutamatergic and dopaminergic terminals are different based on their different sensitivity to anandamide, capsazepine and Gd(3+) at nanomolar concentrations. Altogether, novel ion channels instead of the TRPV(1)R mediate the presynaptic action of N-acyldopamines in the striatum of adult rodents.
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Affiliation(s)
- Samira G Ferreira
- Center for Neuroscience and Cell Biology of Coimbra, Department of Zoology, Faculty of Medicine, University of Coimbra, 1 Rua Larga, 3004-504 Coimbra, Portugal
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22
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Abstract
BACKGROUND Use of capsaicin or resiniferatoxin (RTX) as analgesics is an attractive therapeutic option. RTX opens the cation channel inflammatory pain/vanilloid receptor type 1 (TRPV1) permanently and selectively removes nociceptive neurons by Ca(2+)-cytotoxicity. Paradoxically, not only nociceptors, but non-neuronal cells, including keratinocytes express full length TRPV1 mRNA, while patient dogs and experimental animals that underwent topical treatment or anatomically targeted molecular surgery have shown neither obvious behavioral, nor pathological side effects. METHODS To address this paradox, we assessed the vanilloid sensitivity of the HaCaT human keratinocyte cell line and primary keratinocytes from skin biopsies. RESULTS Although both cell types express TRPV1 mRNA, neither responded to vanilloids with Ca(2+)-cytotoxicity. Only ectopic overproduction of TRPV1 rendered HaCaT cells sensitive to low doses (1-50 nM) of vanilloids. The TRPV1-mediated and non-receptor specific Ca(2+)-cytotoxicity ([RTX]>15 microM) could clearly be distinguished, thus keratinocytes were indeed resistant to vanilloid-induced, TRPV1-mediated Ca(2+)-entry. Having a wider therapeutic window than capsaicin, RTX was effective in subnanomolar range, but even micromolar concentrations could not kill human keratinocytes. Keratinocytes showed orders of magnitudes lower TRPV1 mRNA level than sensory ganglions, the bona fide therapeutic targets in human pain management. In addition to TRPV1, TRPV1b, a dominant negative splice variant was also noted in keratinocytes. CONCLUSION TRPV1B expression, together with low TRPV1 expression, may explain the vanilloid paradox: even genuinely TRPV1 mRNA positive cells can be spared with therapeutic (up to micromolar) doses of RTX. This additional safety information might be useful for planning future human clinical trials.
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Cristino L, Starowicz K, De Petrocellis L, Morishita J, Ueda N, Guglielmotti V, Di Marzo V. Immunohistochemical localization of anabolic and catabolic enzymes for anandamide and other putative endovanilloids in the hippocampus and cerebellar cortex of the mouse brain. Neuroscience 2008; 151:955-68. [DOI: 10.1016/j.neuroscience.2007.11.047] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2007] [Revised: 11/15/2007] [Accepted: 12/20/2007] [Indexed: 10/22/2022]
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24
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Starowicz K, Maione S, Cristino L, Palazzo E, Marabese I, Rossi F, de Novellis V, Di Marzo V. Tonic endovanilloid facilitation of glutamate release in brainstem descending antinociceptive pathways. J Neurosci 2007; 27:13739-49. [PMID: 18077685 PMCID: PMC6673635 DOI: 10.1523/jneurosci.3258-07.2007] [Citation(s) in RCA: 136] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2007] [Revised: 09/24/2007] [Accepted: 10/24/2007] [Indexed: 01/09/2023] Open
Abstract
Activation of transient receptor potential vanilloid-1 (TRPV1) channels in the periaqueductal gray (PAG) activates OFF antinociceptive neurons of the rostral ventromedial medulla (RVM). We examined in rats the effect of intra-ventrolateral (VL)-PAG injections of TRPV1 agonists and antagonists on the nocifensive response to heat in the plantar test, neurotransmitter (glutamate and GABA) release in the RVM, and spontaneous and tail flick-related activities of RVM neurons. The localization of TRPV1 in VL-PAG and RVM neurons was examined using various markers of glutamatergic and GABAergic neurons. Intra-VL-PAG injection of capsaicin increased the threshold of thermal pain sensitivity, whereas the selective TRPV1 antagonist 5'-iodo-resiniferatoxin (I-RTX) facilitated nociceptive responses, and blocked capsaicin analgesic effect at a dose inactive per se. Intra-VL PAG capsaicin evoked a robust release of glutamate in RVM microdialysates. I-RTX, at a dose inactive per se, blocked the effect of capsaicin, and inhibited glutamate release at a higher dose. Antinociception and hyperalgesia induced by capsaicin and I-RTX, respectively, correlated with enhanced or reduced activity of RVM OFF cells. Immunohistochemical analyses suggested that several TRPV1-immunoreactive (ir) neurons in both the VL-PAG and RVM are glutamatergic and surrounded by glutamatergic and GABAergic terminals. Our data suggest that VL-PAG neurons respond to TRPV1 stimulation by releasing glutamate into the RVM, thereby activating OFF cells and producing analgesia. The results obtained with the TRPV1 antagonist alone suggest that this pathway is tonically activated by endovanilloids.
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Affiliation(s)
| | - Sabatino Maione
- Department of Experimental Medicine, Section of Pharmacology “L. Donatelli,” Second University of Naples, 80138 Naples, Italy
| | - Luigia Cristino
- Institute of Cybernetics “E. Caianiello,” Consiglio Nazionale delle Ricerche, 80078 Pozzuoli, Naples, Italy, and
| | - Enza Palazzo
- Department of Experimental Medicine, Section of Pharmacology “L. Donatelli,” Second University of Naples, 80138 Naples, Italy
| | - Ida Marabese
- Department of Experimental Medicine, Section of Pharmacology “L. Donatelli,” Second University of Naples, 80138 Naples, Italy
| | - Francesca Rossi
- Department of Experimental Medicine, Section of Pharmacology “L. Donatelli,” Second University of Naples, 80138 Naples, Italy
| | - Vito de Novellis
- Department of Experimental Medicine, Section of Pharmacology “L. Donatelli,” Second University of Naples, 80138 Naples, Italy
| | - Vincenzo Di Marzo
- The Endocannabinoid Research Group, Institute of Biomolecular Chemistry and
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Bisogno T, Martire A, Petrosino S, Popoli P, Di Marzo V. Symptom-related changes of endocannabinoid and palmitoylethanolamide levels in brain areas of R6/2 mice, a transgenic model of Huntington's disease. Neurochem Int 2007; 52:307-13. [PMID: 17664017 DOI: 10.1016/j.neuint.2007.06.031] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2007] [Revised: 06/18/2007] [Accepted: 06/28/2007] [Indexed: 11/17/2022]
Abstract
Previous studies have shown an impairment of the endocannabinoid system in experimental models of Huntington's disease. In transgenic R6/2 mice, created by inserting exon 1 of the human IT15 mutant gene into the mouse, and exhibiting 150 CAG repeats as well as signs of HD, a progressive decline of CB(1) receptor expression and an abnormal sensitivity to CB(1) receptor stimulation have been reported. Here, by using isotope-dilution liquid chromatography-mass spectrometry, we investigated whether the levels of three endogenous neuroprotective substances, the endocannabinoids anandamide (AEA) and 2-arachidonoylglycerol (2-AG), and palmitoylethanolamide (PEA), are altered in different brain areas of transgenic R6/2 versus wild-type (WT) mice at two different disease phases, i.e. in pre-symptomatic (4.5 weeks) or overtly symptomatic (10 weeks) R6/2 mice versus age-matched WT mice (n=4/group). Except for a approximately 25% decrease in 2-AG levels in the cortex, no significant changes in endocannabinoid and PEA levels were observed in pre-symptomatic R6/2 versus WT mice. By contrast, in symptomatic R6/2 mice the levels of all three compounds were significantly (approximately 30-60%) decreased in the striatum, whereas little changes were observed in the hippocampus, and a approximately 28% decrease of 2-AG levels, accompanied by a approximately 50% increase of AEA levels, was found in the cortex. These findings show that endocannabinoid levels change in a disease phase- and region-specific way in the brain of R6/2 mice and indicate that an impaired endocannabinoid system is a hallmark of symptomatic HD, thus suggesting that drugs inhibiting endocannabinoid degradation might be used to treat this disease.
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Affiliation(s)
- Tiziana Bisogno
- Endocannabinoid Research Group, Institute of Biomolecular Chemistry, Consiglio Nazionale delle Ricerche, Via Campi Flegrei 34, 80078 Pozzuoli, Naples, Italy
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26
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Benninger F, Freund TF, Hájos N. Control of excitatory synaptic transmission by capsaicin is unaltered in TRPV1 vanilloid receptor knockout mice. Neurochem Int 2007; 52:89-94. [PMID: 17651868 PMCID: PMC2194163 DOI: 10.1016/j.neuint.2007.06.008] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2007] [Revised: 06/14/2007] [Accepted: 06/15/2007] [Indexed: 11/05/2022]
Abstract
Several studies have shown that capsaicin could effectively regulate excitatory synaptic transmission in the central nervous system, but the assumption that this effect is mediated by TRPV1 vanilloid receptors (TRPV1Rs) has not been tested directly. To provide direct evidence, we compared the effect of capsaicin on excitatory synapses in wild type mice and TRPV1R knockouts. Using whole-cell patch-clamp techniques, excitatory postsynaptic currents (EPSCs) were recorded in granule cells of the dentate gyrus. First, we investigated the effect of capsaicin on EPSCs evoked by focal stimulation of fibers in the stratum moleculare. Bath application of 10 μM capsaicin reduced the amplitude of evoked EPSCs both in wild type and TRPV1R knockout animals to a similar extent. Treatment of the slices with the TRPV1R antagonist capsazepine (10 μM) alone, or together with the agonist capsaicin, also caused a decrease in the EPSC amplitude both in wild type and TRPV1R knockout animals. Both drugs appeared to affect the efficacy of excitatory synapses at presynaptic sites, since a significant increase was observed in paired-pulse ratio of EPSC amplitude after drug treatment. Next we examined the effect of capsaicin on spontaneously occurring EPSCs. This prototypic vanilloid ligand increased the frequency of events without changing their amplitude in wild type mice. Similar enhancement in the frequency without altering the amplitude of spontaneous EPSCs was observed in TRPV1R knockout mice. These data strongly argue against the hypothesis that capsaicin modulates excitatory synaptic transmission by activating TRPV1Rs, at least in the hippocampal network.
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Affiliation(s)
| | | | - Norbert Hájos
- Corresponding author. Tel.: +36 1 2109400x387; fax: +36 1 2109412.
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Köfalvi A, Pereira MF, Rebola N, Rodrigues RJ, Oliveira CR, Cunha RA. Anandamide and NADA bi-directionally modulate presynaptic Ca2+ levels and transmitter release in the hippocampus. Br J Pharmacol 2007; 151:551-63. [PMID: 17435795 PMCID: PMC2013959 DOI: 10.1038/sj.bjp.0707252] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND AND PURPOSE Inhibitory CB(1) cannabinoid receptors and excitatory TRPV(1) vanilloid receptors are abundant in the hippocampus. We tested if two known hybrid endocannabinoid/endovanilloid substances, N-arachidonoyl-dopamine (NADA) and anandamide (AEA), presynapticaly increased or decreased intracellular calcium level ([Ca(2+)](i)) and GABA and glutamate release in the hippocampus. EXPERIMENTAL APPROACH Resting and K(+)-evoked levels of [Ca(2+)](i) and the release of [(3)H]GABA and [(3)H]glutamate were measured in rat hippocampal nerve terminals. KEY RESULTS NADA and AEA per se triggered a rise of [Ca(2+)](i) and the release of both transmitters in a concentration- and external Ca(2+)-dependent fashion, but independently of TRPV(1), CB(1), CB(2), or dopamine receptors, arachidonate-regulated Ca(2+)-currents, intracellular Ca(2+) stores, and fatty acid metabolism. AEA was recently reported to block TASK-3 potassium channels thereby depolarizing membranes. Common inhibitors of TASK-3, Zn(2+), Ruthenium Red, and low pH mimicked the excitatory effects of AEA and NADA, suggesting that their effects on [Ca(2+)](i) and transmitter levels may be attributable to membrane depolarization upon TASK-3 blockade. The K(+)-evoked Ca(2+) entry and Ca(2+)-dependent transmitter release were inhibited by nanomolar concentrations of the CB(1) receptor agonist WIN55212-2; this action was sensitive to the selective CB(1) receptor antagonist AM251. However, in the low micromolar range, WIN55212-2, NADA and AEA inhibited the K(+)-evoked Ca(2+) entry and transmitter release independently of CB(1) receptors, possibly through direct Ca(2+) channel blockade. CONCLUSIONS AND IMPLICATIONS We report here for hybrid endocannabinoid/endovanilloid ligands novel dual functions which were qualitatively similar to activation of CB(1) or TRPV(1) receptors, but were mediated through interactions with different targets.
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Affiliation(s)
- A Köfalvi
- Center for Neurosciences of Coimbra, University of Coimbra, Coimbra, Portugal.
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Ryan D, Drysdale AJ, Pertwee RG, Platt B. Interactions of cannabidiol with endocannabinoid signalling in hippocampal tissue. Eur J Neurosci 2007; 25:2093-102. [PMID: 17419758 DOI: 10.1111/j.1460-9568.2007.05448.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The phytocannabinoid cannabidiol (CBD) possesses no psychotropic activity amid potentially beneficial therapeutic applications. We here characterized interactions between CBD (1 microM) and the endocannabinoid system in cultured rat hippocampal cells. The CBD-induced Ca2+ rise observed in neurons and glia was markedly reduced in the presence of the endogenous cannabinoid anandamide in neurons, with no alteration seen in glia. Neuronal CBD responses were even more reduced in the presence of the more abundant endocannabinoid 2-arachidonyl glycerol, this action was maintained in the presence of the CB1 receptor antagonist AM281 (100 nM). Neuronal CBD responses were also reduced by pre-exposure to glutamate, expected to increase endocannabinoid levels by increasing in [Ca2+]i. Application of AM281 at 1 microM elevated CBD-induced Ca2+ responses in both cell types, further confirming our finding that endocannabinoid-mediated signalling is negatively coupled to the action of CBD. However, upregulation of endogenous levels of endocannabinoids via inhibition of endocannabinoid hydrolysis (with URB597 and MAFP) could not be achieved under resting conditions. Because delta9-tetrahydrocannabinol did not mimic the endocannabinoid actions, and pertussis toxin treatment had no effect on CBD responses, we propose that the effects of AM281 were mediated via a constitutively active signalling pathway independent of CB1 signalling. Instead, signalling via G(q/11) and phospholipase C appears to be negatively coupled to CBD-induced Ca2+ responses, as the inhibitor U73122 enhanced CBD responses. Our data highlight the interaction between exogenous and endogenous cannabinoid signalling, and provide evidence for the presence of an additional pharmacological target, sensitive to endocannabinoids and to AM281.
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Affiliation(s)
- Duncan Ryan
- School of Medical Sciences, College of Life Sciences and Medicine, University of Aberdeen, Institute of Medical Sciences, Foresterhill, Aberdeen AB25 2ZD Scotland, UK
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29
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Starowicz K, Nigam S, Di Marzo V. Biochemistry and pharmacology of endovanilloids. Pharmacol Ther 2007; 114:13-33. [PMID: 17349697 DOI: 10.1016/j.pharmthera.2007.01.005] [Citation(s) in RCA: 275] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2007] [Accepted: 01/24/2007] [Indexed: 11/28/2022]
Abstract
Endovanilloids are defined as endogenous ligands and activators of transient receptor potential (TRP) vanilloid type 1 (TRPV1) channels. The first endovanilloid to be identified was anandamide (AEA), previously discovered as an endogenous agonist of cannabinoid receptors. In fact, there are several similarities, in terms of opposing actions on the same intracellular signals, role in the same pathological conditions, and shared ligands and tissue distribution, between TRPV1 and cannabinoid CB(1) receptors. After AEA and some of its congeners (the unsaturated long chain N-acylethanolamines), at least 2 other families of endogenous lipids have been suggested to act as endovanilloids: (i) unsaturated long chain N-acyldopamines and (ii) some lipoxygenase (LOX) metabolites of arachidonic acid (AA). Here we discuss the mechanisms for the regulation of the levels of the proposed endovanilloids, as well as their TRPV1-mediated pharmacological actions in vitro and in vivo. Furthermore, we outline the possible pathological conditions in which endovanilloids, acting at sometimes aberrantly expressed TRPV1 receptors, might play a role.
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Affiliation(s)
- Katarzyna Starowicz
- Institute of Biomolecular Chemistry, Endocannabinoid Research Group, C.N.R., Pozzuoli, Naples, Italy
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Abstract
Two major approaches have been employed for the development of novel drugs to treat chronic pain. The most traditional approach identifies molecules involved in pain as potential therapeutic targets and has focused mainly on the periphery and spinal cord. A more recent approach identifies molecules that are involved in long-term plasticity. Drugs developed through the latter approach are predicted to treat chronic, but not physiological or acute, pain. The TRPV1 (transient receptor potential vanilloid-1) receptor is involved in nociceptive processing, and is a candidate therapeutic target for pain. While most research on TRPV1 receptors has been conducted at the level of the spinal cord and peripheral structures, considerably less research has focused on supraspinal structures. This short paper summarizes progress made on TRPV1 receptors, and reviews research on the expression and function of TRPV1 receptors in supraspinal structures. We suggest that the TRPV1 receptor may be involved in pain processing in higher brain structures, such as the anterior cingulate cortex. In addition, some regions of the brain utilize the TRPV1 receptor for functions apparently unrelated to pain.
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Affiliation(s)
- Hendrik W Steenland
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Canada
| | - Shanelle W Ko
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Canada
| | - Long-Jun Wu
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Canada
| | - Min Zhuo
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Canada
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Berghuis P, Dobszay MB, Ibanez RM, Ernfors P, Harkany T. Turning the heterogeneous into homogeneous: studies on selectively isolated GABAergic interneuron subsets. Int J Dev Neurosci 2004; 22:533-43. [PMID: 15465283 DOI: 10.1016/j.ijdevneu.2004.07.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2004] [Accepted: 07/12/2004] [Indexed: 01/23/2023] Open
Abstract
The amazing morphological and electrophysiological diversity of cortical GABAergic interneurons subserves the broad diversity of processes these cells modulate in neuronal networks. Until recently, interneuron development and functions have been extensively studied in heterogeneous in vitro and in vivo systems containing both excitatory and inhibitory components. However, mechanisms of interneuron specification during development, key signaling mechanisms controlling the establishment of particular inhibitory neuron subsets, and the spatial and temporal regulation of their integration in neuronal microcircuits remain poorly understood. Selective isolation of particular interneuron subsets may significantly extend our knowledge on the scenario of neurochemical and electrophysiological specification of developing interneurons, identification of signaling cues directing their axon growth, and principles of their anterograde and retrograde synaptic communication with other cell types. Here, we show that selective isolation of perisomatic inhibitory cells containing either parvalbumin or cholecystokinin reveals major differences in the temporal dynamics of their functional differentiation, and their dependence on target-derived signals like brain-derived neurotrophic factor and endocannabinoids. In addition, we discuss therapeutic prospects of modulating increased excitatory output in the hippocampus and subthalamic nucleus by re-adjusting the inhibitory control of principal cells.
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Affiliation(s)
- Paul Berghuis
- Department of Medical Biochemistry and Biophysics, Laboratory for Molecular Neurobiology, Scheeles väg 1:A1, Karolinska Institutet, S-17177 Stockholm, Sweden
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