当前位置： SCI文献检索 > BRAIN RESEARCH期刊下所有文献 > Responses from osmosensitive neurons of the rat subfornical organ in vitro.

Responses from osmosensitive neurons of the rat subfornical organ in vitro.

Abstract：

:Extracellular recordings were made in vitro from 212 single units in the rat subfornical organ (SFO) and 54 single units in the rat medial preoptic area (MPO). Units were exposed to solutions made hyper-osmotic or hypo-osmotic by 1.4-11%. A reversible 30% or greater change in frequency followed the osmotic challenge in tests of 66% of units in the SFO and 46% of units in the MPO. Responses consisted of increases in frequency (excitations) or decreases in frequency (inhibitions) and were either sustained for the whole test period or of a transitory nature. Units responded to either hyperosmotic (SFO, 19%; MPO, 43%) or to hypo-osmotic changes (SFO, 30%; MPO, 28.5%) or to both (SFO, 51%; MPO, 28.5%). The response pattern of the SFO and MPO was significantly different (chi 2 54.0, 3df, P = 0.0001). In both the SFO and MPO the stimulus to which the units responded was a change in tonicity. This was indicated by the findings that similar responses were evoked by hyperosmotic changes made with either mannitol or NaCl and there was no response to solutions containing urea, either as an additive, or as a substitute for NaCl. In the SFO, in the presence of synaptic blockade produced by raising the Mg concentration in the bathing solution to 15 mM, the frequency of 19/27 units fell significantly. Responses of 40% of units to osmotic pressure changes were blocked indicating these responses were synaptically evoked. The responses which survived synaptic blockade when compared with pre-blockade responses were more often transient (P less than 0.02) and more often inhibitions. Post blockade there were also significantly more responses in the SFO to hypo-osmotic than to hyper-osmotic changes (P = 0.01). Our results suggest that while an ability to change their firing rate in response to small changes of osmotic pressure may be a general property of neurons, the neurons of the SFO are specialised for the detection of changes in the extracellular osmotic pressure.

journal_name

Brain Res

journal_title

Brain research

authors

Sibbald JR,Hubbard JI,Sirett NE

doi

10.1016/0006-8993(88)90251-x

subject

Has Abstract

pub_date

1988-10-04 00:00:00

pages

205-14

issue

eissn

0006-8993

issn

1872-6240

pii

0006-8993(88)90251-X

journal_volume

461

pub_type

杂志文章

在线工具

Responses from osmosensitive neurons of the rat subfornical organ in vitro.