[The state-dependent action of neuropeptides and monoamines on the background neuronal activity of the medial septal area in hibernating animals].
Neuronal activity of the medial septal area (MS-DB) was recorded extracellularly in brain slices from two groups of Yakutian ground squirrels Citellus undulatus--hibernating (winter period) and actively waking (summer period). Effects of three neuropeptides identified in the brain of hibernators (TSKYR, TSKY, and DY) and of two monoamines (serotonin and noradrenaline) on spontaneous activity were analyzed. All neuropeptides reversibly changed the levels of the background activity, but in the hibernating ground squirrels (HGS) the level of reactivity (47-56%) was significantly higher than in the waking ground squirrels (WGS, 25-30%). Serotonin also showed some tendency to higher efficacy in the HGS. Only noradrenaline was equally effective and had absolutely dominating excitatory effect in both states, although the level of excitation in the HGS was higher. All other substances evoked excitatory and inhibitory effects in various proportions. Their distribution was state-dependent, the rate of development, intensity and duration of the effects were greater in the HGS. The experiments confirmed the data on higher excitability and reactivity of the septal neurons in the state of hibernation. It is suggested that the tested neuropeptides may participate in the control of hibernation.
Zenchenko
K I
KI
Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino.
Kokoz
Iu M
IuM
Ivanov
V T
VT
Ziganshin
R Kh
RKh
Vinogradova
O S
OS
D000818:Animals; D015306:Biogenic Monoamines / Q000494:pharmacology*; D004151:Dipeptides / Q000494:pharmacology; D004723:Endorphins / Q000494:pharmacology; D006605:Hibernation / Q000187:drug effects* / Q000502:physiology; D008839:Microelectrodes; D009474:Neurons / Q000187:drug effects* / Q000502:physiology; D009479:Neuropeptides / Q000494:pharmacology*; D009638:Norepinephrine / Q000494:pharmacology; D010446:Peptide Fragments / Q000494:pharmacology; D012589:Sciuridae; D012621:Seasons; D020665:Septum of Brain / Q000187:drug effects* / Q000502:physiology; D012701:Serotonin / Q000494:pharmacology; D013237:Stereoisomerism
D015306:Biogenic Monoamines; D004151:Dipeptides; D004723:Endorphins; D009479:Neuropeptides; D010446:Peptide Fragments; C100744:neokyotorphin (1-4); C078779:aspartyltyrosine; D012701:Serotonin; C036450:neo-kyotorphin; D009638:Norepinephrine