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Jiang W, Kakizaki T, Fujihara K, Miyata S, Zhang Y, Suto T, Kato D, Saito S, Shibasaki K, Ishizaki Y, Isoda K, Yokoo H, Obinata H, Hirano T, Miyasaka Y, Mashimo T, Yanagawa Y. Impact of GAD65 and/or GAD67 deficiency on perinatal development in rats. FASEB J 2022; 36:e22123. [PMID: 34972242 DOI: 10.1096/fj.202101389r] [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: 09/03/2021] [Revised: 11/26/2021] [Accepted: 12/13/2021] [Indexed: 11/11/2022]
Abstract
GABA is a major neurotransmitter in the mammalian central nervous system. Glutamate decarboxylase (GAD) synthesizes GABA from glutamate, and two isoforms of GAD, GAD65, and GAD67, are separately encoded by the Gad2 and Gad1 genes, respectively. The phenotypes differ in severity between GAD single isoform-deficient mice and rats. For example, GAD67 deficiency causes cleft palate and/or omphalocele in mice but not in rats. In this study, to further investigate the functional roles of GAD65 and/or GAD67 and to determine the contribution of these isoforms to GABA synthesis during development, we generated various kinds of GAD isoform(s)-deficient rats and characterized their phenotypes. The age of death was different among Gad mutant rat genotypes. In particular, all Gad1-/- ; Gad2-/- rats died at postnatal day 0 and showed little alveolar space in their lungs, suggesting that the cause of their death was respiratory failure. All Gad1-/- ; Gad2-/- rats and 18% of Gad1-/- ; Gad2+/- rats showed cleft palate. In contrast, none of the Gad mutant rats including Gad1-/- ; Gad2-/- rats, showed omphalocele. These results suggest that both rat GAD65 and GAD67 are involved in palate formation, while neither isoform is critical for abdominal wall formation. The GABA content in Gad1-/- ; Gad2-/- rat forebrains and retinas at embryonic day 20 was extremely low, indicating that almost all GABA was synthesized from glutamate by GADs in the perinatal period. The present study shows that Gad mutant rats are a good model for further defining the role of GABA during development.
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Affiliation(s)
- Weiru Jiang
- Department of Genetic and Behavioral Neuroscience, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Toshikazu Kakizaki
- Department of Genetic and Behavioral Neuroscience, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Kazuyuki Fujihara
- Department of Genetic and Behavioral Neuroscience, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Shigeo Miyata
- Department of Genetic and Behavioral Neuroscience, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Yue Zhang
- Department of Genetic and Behavioral Neuroscience, Gunma University Graduate School of Medicine, Maebashi, Japan.,Liaoning Provincial Key Laboratory of Cerebral Diseases, Department of Physiology, Dalian Medical University, Dalian, China
| | - Takashi Suto
- Department of Anesthesiology, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Daiki Kato
- Department of Anesthesiology, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Shigeru Saito
- Department of Anesthesiology, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Koji Shibasaki
- Department of Molecular and Cellular Neurobiology, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Yasuki Ishizaki
- Department of Molecular and Cellular Neurobiology, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Koji Isoda
- Department of Human Pathology, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Hideaki Yokoo
- Department of Human Pathology, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Hideru Obinata
- Laboratory for Analytical Instruments, Education and Research Support Center, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Touko Hirano
- Laboratory for Analytical Instruments, Education and Research Support Center, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Yoshiki Miyasaka
- Institute of Experimental Animal Sciences, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Tomoji Mashimo
- Laboratory Animal Research Center, Institute of Medical Science, The University of Tokyo, Tokyo, Japan
| | - Yuchio Yanagawa
- Department of Genetic and Behavioral Neuroscience, Gunma University Graduate School of Medicine, Maebashi, Japan
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Klemz A, Kreis P, Eickholt BJ, Gerevich Z. The actin binding protein drebrin helps to protect against the development of seizure-like events in the entorhinal cortex. Sci Rep 2021; 11:8662. [PMID: 33883605 PMCID: PMC8060314 DOI: 10.1038/s41598-021-87967-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 03/31/2021] [Indexed: 11/09/2022] Open
Abstract
The actin binding protein drebrin plays a key role in dendritic spine formation and synaptic plasticity. Decreased drebrin protein levels have been observed in temporal lobe epilepsy, suggesting the involvement of drebrin in the disease. Here we investigated the effect of drebrin knockout on physiological and pathophysiological neuronal network activities in mice by inducing gamma oscillations, involved in higher cognitive functions, and by analyzing pathophysiological epileptiform activity. We found that loss of drebrin increased the emergence of spontaneous gamma oscillations suggesting an increase in neuronal excitability when drebrin is absent. Further analysis showed that although the kainate-induced hippocampal gamma oscillations were unchanged in drebrin deficient mice, seizure like events measured in the entorhinal cortex appeared earlier and more frequently. The results suggest that while drebrin is not essential for normal physiological network activity, it helps to protect against the formation of seizure like activities during pathological conditions. The data indicate that targeting drebrin function could potentially be a preventive or therapeutic strategy for epilepsy treatment.
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Affiliation(s)
- Alexander Klemz
- Institute of Neurophysiology, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Patricia Kreis
- Institute of Biochemistry, Charité-Universitätsmedizin Berlin, 10117, Berlin, Germany.
| | - Britta J Eickholt
- Institute of Biochemistry, Charité-Universitätsmedizin Berlin, 10117, Berlin, Germany
| | - Zoltan Gerevich
- Institute of Neurophysiology, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany.
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Miyata S, Kakizaki T, Fujihara K, Obinata H, Hirano T, Nakai J, Tanaka M, Itohara S, Watanabe M, Tanaka KF, Abe M, Sakimura K, Yanagawa Y. Global knockdown of glutamate decarboxylase 67 elicits emotional abnormality in mice. Mol Brain 2021; 14:5. [PMID: 33413507 PMCID: PMC7789591 DOI: 10.1186/s13041-020-00713-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 12/07/2020] [Indexed: 11/11/2022] Open
Abstract
Reduced expression of glutamate decarboxylase 67 (GAD67), encoded by the Gad1 gene, is a consistent finding in postmortem brains of patients with several psychiatric disorders, including schizophrenia, bipolar disorder and major depressive disorder. The dysfunction of GAD67 in the brain is implicated in the pathophysiology of these psychiatric disorders; however, the neurobiological consequences of GAD67 dysfunction in mature brains are not fully understood because the homozygous Gad1 knockout is lethal in newborn mice. We hypothesized that the tetracycline-controlled gene expression/suppression system could be applied to develop global GAD67 knockdown mice that would survive into adulthood. In addition, GAD67 knockdown mice would provide new insights into the neurobiological impact of GAD67 dysfunction. Here, we developed Gad1tTA/STOP−tetO biallelic knock-in mice using Gad1STOP−tetO and Gad1tTA knock-in mice, and compared them with Gad1+/+ mice. The expression level of GAD67 protein in brains of Gad1tTA/STOP−tetO mice treated with doxycycline (Dox) was decreased by approximately 90%. The GABA content was also decreased in the brains of Dox-treated Gad1tTA/STOP−tetO mice. In the open-field test, Dox-treated Gad1tTA/STOP−tetO mice exhibited hyper-locomotor activity and decreased duration spent in the center region. In addition, acoustic startle responses were impaired in Dox-treated Gad1tTA/STOP−tetO mice. These results suggest that global reduction in GAD67 elicits emotional abnormalities in mice. These GAD67 knockdown mice will be useful for elucidating the neurobiological mechanisms of emotional abnormalities, such as anxiety symptoms associated with psychiatric disorders.
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Affiliation(s)
- Shigeo Miyata
- Department of Genetic and Behavioral Neuroscience, Gunma University Graduate School of Medicine, Maebashi, 371-8511, Japan.
| | - Toshikazu Kakizaki
- Department of Genetic and Behavioral Neuroscience, Gunma University Graduate School of Medicine, Maebashi, 371-8511, Japan
| | - Kazuyuki Fujihara
- Department of Genetic and Behavioral Neuroscience, Gunma University Graduate School of Medicine, Maebashi, 371-8511, Japan
| | - Hideru Obinata
- Laboratory for Analytical Instruments, Education and Research Support Center, Gunma University Graduate School of Medicine, Maebashi, 371-8511, Japan
| | - Touko Hirano
- Laboratory for Analytical Instruments, Education and Research Support Center, Gunma University Graduate School of Medicine, Maebashi, 371-8511, Japan
| | - Junichi Nakai
- Division of Oral Physiology, Department of Oral Function and Morphology, Tohoku University Graduate School of Dentistry, Sendai, 980-8575, Japan
| | - Mika Tanaka
- Laboratory for Behavioral Genetics, RIKEN Brain Science Institute, Wako, 351-0198, Japan
| | - Shigeyoshi Itohara
- Laboratory for Behavioral Genetics, RIKEN Brain Science Institute, Wako, 351-0198, Japan
| | - Masahiko Watanabe
- Department of Anatomy, Faculty of Medicine, Hokkaido University, Sapporo, 060-8638, Japan
| | - Kenji F Tanaka
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, 160-8582, Japan
| | - Manabu Abe
- Department of Animal Model Development, Brain Research Institute, Niigata University, Niigata, 951-8585, Japan
| | - Kenji Sakimura
- Department of Animal Model Development, Brain Research Institute, Niigata University, Niigata, 951-8585, Japan
| | - Yuchio Yanagawa
- Department of Genetic and Behavioral Neuroscience, Gunma University Graduate School of Medicine, Maebashi, 371-8511, Japan.
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Fujihara K, Sato T, Miyasaka Y, Mashimo T, Yanagawa Y. Genetic deletion of the 67-kDa isoform of glutamate decarboxylase alters conditioned fear behavior in rats. FEBS Open Bio 2020; 11:340-353. [PMID: 33325157 PMCID: PMC7876494 DOI: 10.1002/2211-5463.13065] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 11/24/2020] [Accepted: 12/14/2020] [Indexed: 12/31/2022] Open
Abstract
The GABAergic system is thought to play an important role in the control of cognition and emotion, such as fear, and is related to the pathophysiology of psychiatric disorders. For example, the expression of the 67‐kDa isoform of glutamate decarboxylase (GAD67), a GABA‐producing enzyme, is downregulated in the postmortem brains of patients with major depressive disorder and schizophrenia. However, knocking out the Gad1 gene, which encodes GAD67, is lethal in mice, and thus, the association between Gad1 and cognitive/emotional functions is unclear. We recently developed Gad1 knockout rats and found that some of them can grow into adulthood. Here, we performed fear‐conditioning tests in adult Gad1 knockout rats to assess the impact of the loss of Gad1 on fear‐related behaviors and the formation of fear memory. In a protocol assessing both cued and contextual memory, Gad1 knockout rats showed a partial antiphase pattern of freezing during training and significantly excessive freezing during the contextual test compared with wild‐type rats. However, Gad1 knockout rats did not show any synchronous increase in freezing with auditory tones in the cued test. On the other hand, in a contextual memory specialized protocol, Gad1 knockout rats exhibited comparable freezing behavior to wild‐type rats, while their fear extinction was markedly impaired. These results suggest that GABA synthesis by GAD67 has differential roles in cued and contextual fear memory.
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Affiliation(s)
- Kazuyuki Fujihara
- Departments of Genetic and Behavioral Neuroscience, Graduate School of Medicine, Gunma University, Maebashi, Japan.,Department of Psychiatry and Neuroscience, Graduate School of Medicine, Gunma University, Maebashi, Japan
| | - Takumi Sato
- Departments of Genetic and Behavioral Neuroscience, Graduate School of Medicine, Gunma University, Maebashi, Japan
| | - Yoshiki Miyasaka
- Institute of Experimental Animal Sciences, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Tomoji Mashimo
- Laboratory Animal Research Center, Institute of Medical Science, the University of Tokyo, Japan
| | - Yuchio Yanagawa
- Departments of Genetic and Behavioral Neuroscience, Graduate School of Medicine, Gunma University, Maebashi, Japan
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Kakizaki T, Ohshiro T, Itakura M, Konno K, Watanabe M, Mushiake H, Yanagawa Y. Rats deficient in the GAD65 isoform exhibit epilepsy and premature lethality. FASEB J 2020; 35:e21224. [PMID: 33236473 DOI: 10.1096/fj.202001935r] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 10/27/2020] [Accepted: 11/11/2020] [Indexed: 02/02/2023]
Abstract
GABA is synthesized by glutamate decarboxylase (GAD), which has two isoforms, namely, GAD65 and GAD67, encoded by the Gad2 and Gad1 genes, respectively. GAD65-deficient (Gad2-/- ) mice exhibit a reduction in brain GABA content after 1 month of age and show spontaneous seizures in adulthood. Approximately 25% of Gad2-/- mice died by 6 months of age. Our Western blot analysis demonstrated that the protein expression ratio of GAD65 to GAD67 in the brain was greater in rats than in mice during postnatal development, suggesting that the contribution of each GAD isoform to GABA functions differs between these two species. To evaluate whether GAD65 deficiency causes different phenotypes between rats and mice, we generated Gad2-/- rats using TALEN genome editing technology. Western blot and immunohistochemical analyses with new antibodies demonstrated that the GAD65 protein was undetectable in the Gad2-/- rat brain. Gad2-/- pups exhibited spontaneous seizures and paroxysmal discharge in EEG at postnatal weeks 3-4. More than 80% of the Gad2-/- rats died at postnatal days (PNDs) 17-23. GABA content in Gad2-/- brains was significantly lower than those in Gad2+/- and Gad2+/+ brains at PND17-19. These results suggest that the low levels of brain GABA content in Gad2-/- rats may lead to epilepsy followed by premature death, and that Gad2-/- rats are more severely affected than Gad2-/- mice. Considering that the GAD65/GAD67 ratio in human brains is more similar to that in rat brains than in mouse brains, Gad2-/- rats would be useful for further investigating the roles of GAD65 in vivo.
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Affiliation(s)
- Toshikazu Kakizaki
- Department of Genetic and Behavioral Neuroscience, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Tomokazu Ohshiro
- Department of Physiology, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Makoto Itakura
- Department of Biochemistry, Kitasato University School of Medicine, Sagamihara, Japan
| | - Kohtarou Konno
- Department of Anatomy, Faculty of Medicine, Hokkaido University, Sapporo, Japan
| | - Masahiko Watanabe
- Department of Anatomy, Faculty of Medicine, Hokkaido University, Sapporo, Japan
| | - Hajime Mushiake
- Department of Physiology, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Yuchio Yanagawa
- Department of Genetic and Behavioral Neuroscience, Gunma University Graduate School of Medicine, Maebashi, Japan
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6
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High-content imaging analysis for detecting the loss of drebrin clusters along dendrites in cultured hippocampal neurons. J Pharmacol Toxicol Methods 2019; 99:106607. [DOI: 10.1016/j.vascn.2019.106607] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 06/27/2019] [Accepted: 06/27/2019] [Indexed: 11/18/2022]
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7
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Hanamura K, Kamata Y, Yamazaki H, Kojima N, Shirao T. Isoform-dependent Regulation of Drebrin Dynamics in Dendritic Spines. Neuroscience 2018. [DOI: 10.1016/j.neuroscience.2018.02.038] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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9
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Myosin II ATPase activity mediates the long-term potentiation-induced exodus of stable F-actin bound by drebrin A from dendritic spines. PLoS One 2014; 9:e85367. [PMID: 24465547 PMCID: PMC3899004 DOI: 10.1371/journal.pone.0085367] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Accepted: 11/25/2013] [Indexed: 12/19/2022] Open
Abstract
The neuronal actin-binding protein drebrin A forms a stable structure with F-actin in dendritic spines. NMDA receptor activation causes an exodus of F-actin bound by drebrin A (DA-actin) from dendritic spines, suggesting a pivotal role for DA-actin exodus in synaptic plasticity. We quantitatively assessed the extent of DA-actin localization to spines using the spine-dendrite ratio of drebrin A in cultured hippocampal neurons, and found that (1) chemical long-term potentiation (LTP) stimulation induces rapid DA-actin exodus and subsequent DA-actin re-entry in dendritic spines, (2) Ca2+ influx through NMDA receptors regulates the exodus and the basal accumulation of DA-actin, and (3) the DA-actin exodus is blocked by myosin II ATPase inhibitor, but is not blocked by myosin light chain kinase (MLCK) or Rho-associated kinase (ROCK) inhibitors. These results indicate that myosin II mediates the interaction between NMDA receptor activation and DA-actin exodus in LTP induction. Furthermore, myosin II seems to be activated by a rapid actin-linked mechanism rather than slow MLC phosphorylation. Thus the myosin-II mediated DA-actin exodus might be an initial event in LTP induction, triggering actin polymerization and spine enlargement.
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Roppongi RT, Kojima N, Hanamura K, Yamazaki H, Shirao T. Selective reduction of drebrin and actin in dendritic spines of hippocampal neurons by activation of 5-HT(2A) receptors. Neurosci Lett 2013; 547:76-81. [PMID: 23684573 DOI: 10.1016/j.neulet.2013.04.061] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Revised: 04/27/2013] [Accepted: 04/30/2013] [Indexed: 01/10/2023]
Abstract
Abnormal architecture of dendritic spines is associated with neurodevelopmental and neurodegenerative diseases. The 5-HT(2A) receptor is a potential therapeutic target for mental illnesses and it is functionally and genetically associated with many types of psychiatric disorders. It has been reported that 5-HT(2A) receptor activation alters spine architecture. Although actin cytoskeleton has a key role in the regulation of spine architecture, it is not clarified whether 5-HT(2A)+ receptor activation affect the actin cytoskeleton in dendritic spines. In the present study, we examined the effect of 5-HT(2A) receptor activation on the actin cytoskeleton in dendritic spines of mature hippocampal neurons in low-density culture. Immunocytochemical analysis showed that 15 min exposure of 5-HT(2A) receptor agonist (±)-2,5-dimethoxy-4-iodoamphetamine hydrochloride (DOI) significantly decreased the cluster densities of drebrin (control, 37.0±6.9 per 100 μm, DOI, 12.5±2.9) and F-actin (control, 18.3±4.9; DOI, 7.7±2.1) at dendritic spines without any detectable changes in the cluster densities of synapsin I and PSD-95. At the same time period DOI exposure did not affect spine architecture (spine density: control, 38.3±5.1 per 100 μm; DOI, 25.6±3.5; spine length: control, 1.99±0.18; DOI, 2.00±0.29; spine width: control, 0.72±0.06; DOI, 0.77±0.11). Thus, it is indicated that decrease of drebrin and F-actin can occur at the dendritic spines without morphological changes. Together our data suggest that 5-HT(2A) receptors activation is involved in the regulation of distribution of cytoskeleton in the dendritic spines.
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Affiliation(s)
- Reiko T Roppongi
- Department of Neurobiology and Behavior, Gunma University Graduate School of Medicine, Maebashi, Japan
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Distribution of CaMKIIα expression in the brain in vivo, studied by CaMKIIα-GFP mice. Brain Res 2013; 1518:9-25. [PMID: 23632380 DOI: 10.1016/j.brainres.2013.04.042] [Citation(s) in RCA: 145] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2013] [Revised: 04/17/2013] [Accepted: 04/18/2013] [Indexed: 01/08/2023]
Abstract
To facilitate the study of the CaMKIIα function in vivo, a CaMKIIα-GFP transgenic mouse line was generated. Here, our goal is to provide the first neuroanatomical characterization of GFP expression in the CNS of this line of mouse. Overall, CaMKIIα-GFP expression is strong and highly heterogeneous, with the dentate gyrus of the hippocampus as the most abundantly expressed region. In the hippocampus, around 70% of granule and pyramidal neurons expressed strong GFP. In the neocortex, presumed pyramidal neurons were GFP positive: around 32% of layer II/III and 35% of layer VI neurons expressed GFP, and a lower expression rate was found in other layers. In the thalamus and hypothalamus, strong GFP signals were detected in the neuropil. GFP-positive cells were also found in many other regions such as the spinal trigeminal nucleus, cerebellum and basal ganglia. We further compared the GFP expression with specific antibody staining for CaMKIIα and GABA. We found that GFP+ neurons were mostly positive for CaMKIIα-IR throughout the brain, with some exceptions throughout the brain, especially in the deeper layers of neocortex. GFP and GABA-IR marked distinct neuronal populations in most brain regions with the exception of granule cells in the olfactory bulb, purkinje cells in the cerebellar, and some layer I cells in neocortex. In conclusion, GFP expression in the CaMKIIα-GFP mice is similar to the endogenous expression of CaMKIIα protein, thus these mice can be used in in vivo and in vitro physiological studies in which visualization of CaMKIIα- neuronal populations is required.
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