Extrinsic control of phasic supraoptic neurones in vitro: burst initiation and termination following brief changes in excitatory drive.
Experiments were performed to investigate the responses of phasic supraoptic cells in hypothalamic slices to brief (2-3 sec) changes in excitatory drive, induced by varying the level of local glutamate stimulation. A brief increase in excitation during a silent period immediately triggered a prolonged burst of firing, similar in duration to the ongoing phasic bursts. A transient decrease in excitation during a phasic burst evoked a protracted quiescence, reminiscent of a typical silent period. These results support the idea that in phasic cells the effects of brief synaptic inputs may be amplified in time to produce a prolonged change in electrical activity and associated hormone release.
D000344:Afferent Pathways / Q000502:physiology; D000818:Animals; D046508:Culture Techniques; D004558:Electric Stimulation; D005071:Evoked Potentials / Q000187:drug effects; D005971:Glutamates / Q000494:pharmacology; D018698:Glutamic Acid; D009433:Neural Inhibition / Q000187:drug effects; D009489:Neurosecretion / Q000187:drug effects; D051381:Rats; D013495:Supraoptic Nucleus / Q000502:physiology*; D009435:Synaptic Transmission / Q000187:drug effects
D005971:Glutamates; D018698:Glutamic Acid