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Kobayashi S, Kim J, Yanagawa Y, Suzuki N, Saito H, Takayama C. Hyper-Formation of GABA and Glycine Co-Releasing Terminals in the Mouse Cerebellar Nuclei after Deprivation of GABAergic Inputs from Purkinje Cells. Neuroscience 2019; 426:88-100. [PMID: 31846755 DOI: 10.1016/j.neuroscience.2019.11.030] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 11/11/2019] [Accepted: 11/19/2019] [Indexed: 11/27/2022]
Abstract
GABA and glycine are inhibitory neurotransmitters. However, the mechanisms underlying the formation of GABAergic and glycinergic synapses remain unclear. The influence of GABAergic input deprivation on inhibitory terminal formation was investigated using Purkinje cell (PC)-specific vesicular GABA transporter (VGAT) knockout (L7-VGAT) mice, in which GABA release from PCs diminishes in an age-dependent manner. We compared the late development of GABAergic and glycinergic terminals in the cerebellar nucleus (CN) between control and L7-VGAT mice. In the control CN, the density of glutamate decarboxylase (GAD)-positive dots remained unchanged between postnatal 2 months (P2M) and 13 months (P13M), whereas glycine transporter 2 (GlyT2)-positive dots increased in density during this time frame. No difference in the density of GlyT2-positive dots was observed between control and L7-VGAT mice at P2M, but the density was significantly higher in the L7-VGAT fastigial nuclei (FN) than the control FN at P13M. When VGAT was absent from PC terminals, GlyT2-positive dots included GAD and VGAT and formed synapses. These results indicated that GABAergic terminals were formed by P2M, glycinergic terminals were actively formed after P2M, and more glycinergic terminals were formed in the L7-VGAT FN than in the control FN, suggesting that the increased glycinergic terminals may derive from interneurons within the FN and may also release GABA. These results suggest that the deprivation of GABAergic inputs from PCs may accelerate the formation of co-releasing terminals derived from interneurons and that the inhibitory terminal numbers and types may be regulated by the quantity of functional GABAergic inputs.
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Affiliation(s)
- Shiori Kobayashi
- Department of Molecular Anatomy, School of Medicine, University of the Ryukyus, Uehara 207, Nishihara, Okinawa 9030215, Japan
| | - Jeongtae Kim
- Department of Molecular Anatomy, School of Medicine, University of the Ryukyus, Uehara 207, Nishihara, Okinawa 9030215, Japan; Department of Veterinary Anatomy, College of Veterinary Medicine and Veterinary Medical Research Institute, Jeju National University, Jeju 63243, Republic of Korea
| | - Yuchio Yanagawa
- Department of Genetic and Behavioral Neuroscience, Gunma University Graduate School of Medicine, 3-39-22 Showa-Machi, Maebashi, Gunma 371-8511, Japan
| | - Noboru Suzuki
- Department of Animal Functional Genomics of Advanced Science Research Promotion Center, Mie University Organization for the Promotion of Regional Innovation, 2-174 Edobashi, Tsu, Mie 5148507, Japan
| | - Hiromitsu Saito
- Department of Animal Functional Genomics of Advanced Science Research Promotion Center, Mie University Organization for the Promotion of Regional Innovation, 2-174 Edobashi, Tsu, Mie 5148507, Japan
| | - Chitoshi Takayama
- Department of Molecular Anatomy, School of Medicine, University of the Ryukyus, Uehara 207, Nishihara, Okinawa 9030215, Japan.
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Influence of Temperature on Motor Behaviors in Newborn Opossums ( Monodelphis domestica): An In Vitro Study. eNeuro 2019; 6:ENEURO.0347-18.2019. [PMID: 31097626 PMCID: PMC6553572 DOI: 10.1523/eneuro.0347-18.2019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Revised: 05/03/2019] [Accepted: 05/09/2019] [Indexed: 11/21/2022] Open
Abstract
External thermosensation is crucial to regulate animal behavior and homeostasis, but the development of the mammalian thermosensory system is not well known. We investigated whether temperature could play a role in the control of movements in a mammalian model born very immature, the opossum (Monodelphis domestica). Like other marsupials, at birth the opossum performs alternate and rhythmic movements with its forelimbs (FLs) to reach a teat where it attaches in order to continue its development. It was shown that FL movements can be induced by mechanical stimulation of the snout in in vitro preparations of newborns consisting of the neuraxis with skin and FLs intact. In the present study, we used puff ejections of cold, neutral (bath temperature) and hot liquid directed toward the snout to induce FL responses in such preparations. Either the responses were visually observed under a microscope or triceps muscle activity was recorded. Cold liquid systematically induced FL movements and triceps contractions, but neutral and hot temperatures were less potent to do so. Sections of the trigeminal nerves and removal of the facial skin diminished responses to cold and nearly abolished those to hot and neutral stimulations. Transient receptor potential melastatin 8 (TRPM8) being the major cold receptor cation channel in adult mammals, we employed immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR) to test for its expression, but found that it is not expressed before 13 postnatal days. Overall our results indicate that cold thermosensation exerts a strong influence on motor behaviors in newborn opossums.
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Kobayashi M, Shimizu-Okabe C, Kim J, Kobayashi S, Matsushita M, Masuzaki H, Takayama C. Embryonic development of GABAergic terminals in the mouse hypothalamic nuclei involved in feeding behavior. Neurosci Res 2018; 134:39-48. [PMID: 29174921 DOI: 10.1016/j.neures.2017.11.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2017] [Revised: 10/18/2017] [Accepted: 11/20/2017] [Indexed: 11/29/2022]
Abstract
The inhibitory neurotransmitter gamma-amino butyric acid (GABA) plays important roles in energy balance and feeding behavior in the hypothalamus. To reveal the time course of GABAergic network formation, we examined the immunohistochemical localization of glutamic acid decarboxylase (GAD), a GABAergic neuron marker, vesicular GABA transporter (VGAT), a marker of inhibitory terminals, and K+-Cl--cotransporter2 (KCC2), which shifts GABA action from excitation to inhibition, in the developing mouse hypothalamus. GABAergic terminals, seen as GAD- and VGAT-positive dots, increased in density during embryonic development. Moreover, the onset of KCC2 localization was almost concomitant with GABAergic terminal formation, and KCC2-positive profiles increased in density during development. This suggested that after the formation of GABAergic terminals, GABAergic action may change to inhibition in the hypothalamus. This maturation appears to proceed as follows: the lateral hypothalamus (LH) matures first, followed by the paraventricular nucleus (PVN) by the time of birth, while the ventromedial hypothalamus (VMH) and the arcuate nucleus (Arc) are not fully mature at the time of birth. Our findings suggest that GABAergic networks in the "feeding center" (LH) and the "exit" (PVN) may mature before birth, while those in the "satiety center" (VMH) and "higher control center" (Arc) may mature after birth.
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Affiliation(s)
- Masato Kobayashi
- Department of Molecular Anatomy, School of Medicine, University of the Ryukyus, Uehara 207, Nishihara, Okinawa, 9030215, Japan
| | - Chigusa Shimizu-Okabe
- Department of Molecular Anatomy, School of Medicine, University of the Ryukyus, Uehara 207, Nishihara, Okinawa, 9030215, Japan
| | - Jeongtae Kim
- Department of Molecular Anatomy, School of Medicine, University of the Ryukyus, Uehara 207, Nishihara, Okinawa, 9030215, Japan
| | - Shiori Kobayashi
- Department of Molecular Anatomy, School of Medicine, University of the Ryukyus, Uehara 207, Nishihara, Okinawa, 9030215, Japan
| | - Masayuki Matsushita
- Department of Molecular and Cellular Physiology, School of Medicine, University of the Ryukyus, Okinawa, Japan
| | - Hiroaki Masuzaki
- Division of Endocrinology, Diabetes and Metabolism, Hematology, Rheumatology School of Medicine, University of the Ryukyus, Okinawa, Japan
| | - Chitoshi Takayama
- Department of Molecular Anatomy, School of Medicine, University of the Ryukyus, Uehara 207, Nishihara, Okinawa, 9030215, Japan.
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Kim J, Takayama C, Park C, Ahn M, Moon C, Shin T. Immunohistochemical localization of GABAergic key molecules in the main olfactory bulb of the Korean roe deer, Capreolus pygargus. Acta Histochem 2015; 117:642-8. [PMID: 26115600 DOI: 10.1016/j.acthis.2015.06.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Revised: 05/14/2015] [Accepted: 06/10/2015] [Indexed: 10/23/2022]
Abstract
Gamma-amino butyric acid (GABA) negatively regulates the excitatory activity of neurons and is a predominant neurotransmitter in the nervous system. The olfactory bulb, the main center in the olfactory system, is modulated by inhibitory interneurons that use GABA as their main neurotransmitter. The present study aimed to evaluate GABAergic transmission in the main olfactory bulb (MOB) of the Korean roe deer (Capreolus pygargus) by examining the immunohistochemical localization of GABAergic key molecules, including glutamic acid decarboxylase (GAD), vesicular GABA transporter (VGAT), GABA transporters (GATs; GAT-1 and GAT-3), and potassium sodium chloride co-transporter 2 (KCC2). GAD, VGAT, and KCC2 were expressed in the glomerular layer (GL), external plexiform layer (ePL), mitral cell layer (ML), and granule cell layer (GrL). Intense GAT-1 expression was observed in the GL; GAT-1 expression was discernible in the ePL, ML, and GrL. However, intense GAT-3 expression was extensively observed in all layers of the MOB. These results suggest that substantial GABAergic synapses are present in the GL, ePL, ML, and GrL. Furthermore, the released GABA may be removed by GAT-1 and GAT-3 in the GL, and the majority of GABA, which is present in the ePL to GrL, may undergo reuptake by GAT-3. This is the first morphological and descriptive study of GABAergic transmission in the MOB of Korean roe deer.
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Affiliation(s)
- Jeongtae Kim
- Department of Molecular Anatomy, Faculty of Medicine, University of the Ryukyus, Uehara 207, Nishihara, Okinawa 903 0215, Japan
| | - Chitoshi Takayama
- Department of Molecular Anatomy, Faculty of Medicine, University of the Ryukyus, Uehara 207, Nishihara, Okinawa 903 0215, Japan
| | - Changnam Park
- Department of Veterinary Anatomy, College of Veterinary Medicine, Jeju National University, Jeju 690 756, Republic of Korea
| | - Meejung Ahn
- School of Medicine, Jeju National University, Jeju 690 756, Republic of Korea
| | - Changjong Moon
- Department of Veterinary Anatomy, College of Veterinary Medicine, Chonnam National University, 300 Yongbong-Dong, Buk-Gu, Gwangju 500 757, Republic of Korea.
| | - Taekyun Shin
- Department of Veterinary Anatomy, College of Veterinary Medicine, Jeju National University, Jeju 690 756, Republic of Korea.
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