Postnatal development of inhibitory synaptic transmission to superior salivatory neurons in rats.
The primary parasympathetic center of the submandibular and sublingual salivary glands is the superior salivatory (SS) nucleus, and its neurons receive excitatory (glutamatergic) and inhibitory (GABAergic and glycinergic) synaptic transmissions in rats. In the present study, we focused on the postnatal development of inhibitory transmission to SS neurons. Gramicidin-perforated whole-cell patch-clamp recordings were performed in rat brainstem slices on postnatal day 2 (P2)-P14. Developmental changes in the intracellular Cl(-) concentration ([Cl(-)](in)) were examined based on the reversal potentials of total inhibitory postsynaptic currents (GABAergic plus glycinergic), which were evoked by electrical stimulation near the recording neuron. The [Cl(-)](in) in the P8-P14 group was significantly lower than in the P2-P7 group. The effect of GABA application at the resting potentials changed from depolarization to hyperpolarization around P8, suggesting that SS neurons acquired mature inhibitory systems around P8. The period at which GABA responses change from excitatory to inhibitory in SS neurons was discussed compared with those of the forebrain, brainstem, and spinal neurons.
Department of Oral Physiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan.
Yoshihiro
Y
Mitoh
Makoto
M
Funahashi
Masako
M
Fujita
Motoi
M
Kobashi
Ryuji
R
Matsuo
D000818:Animals; D002712:Chlorides / Q000378:metabolism; D005998:Glycine / Q000378:metabolism; D008526:Medulla Oblongata / Q000254:growth & development* / Q000502:physiology*; D023421:Models, Animal; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D018408:Patch-Clamp Techniques; D051381:Rats; D017208:Rats, Wistar; D012469:Salivary Glands / Q000294:innervation*; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology*; D005680:gamma-Aminobutyric Acid / Q000378:metabolism / Q000494:pharmacology
D002712:Chlorides; D005680:gamma-Aminobutyric Acid; D005998:Glycine