Penetration of fluorescein into the brain: a sex difference.

Fluorescein was found to penetrate into the brain via the circumventricular organs. Fluorescein penetrates beyond the borders of the circumventricular organs into the surrounding neuropile. This relationship was found for the area postrema and the nucleus tractus solitarius, the organum vasculosum lamina terminalis and the rostral suprachiasmatic area, the median eminence and the arcuate nucleus.

Blood pressure following microinjection of somatostatin related peptides into the rat nucleus tractus solitarii.

The possible role of medullary somatostatin as a neurotransmitter involved in blood pressure regulation was examined. Blood pressure and heart rate were measured in pentobarbital anesthetized rats while pmol quantities of somatostatin-28 (SS28), SS28-(15-28) (somatostatin-14), SS28-(1-12) or SS28-(1-10) were injected into the caudal nucleus tractus solitarii (NTS). Injection of artificial cerebrospinal fluid (ACSF; 500 nl/10 s) alone was followed by a small (2 mmHg) statistically insignificant decrease in blood pressure.

Synaptic responses of neurons of the nucleus tractus solitarius in vitro.

Postsynaptic responses of neurons in the nucleus tractus solitarius (NTS) have been studied in an in vitro slice preparation using extra- and intracellular recording. Single or paired pulse stimulations were delivered to afferent fibers within the tractus solitarius (TS) to activate orthodromic responses in these neurons. Most NTS neurons displayed an initial synaptic excitation followed by inhibition of spontaneous or evoked firing lasting up to 150-200 ms after stimulation.

Hypotensive response of ethanol in rats pretreated with disulfiram or nitrefazole.

The effect of disulfiram or nitrefazole pretreatment on ethanol induced hypotension was examined in urethane anesthetized rats. A relatively low dose of ethanol (150 mg/kg; i.p.

Rat blood pressure during ethanol withdrawal.

Hypertension appears to be a clinical sign of ethanol withdrawal. In an effort to see if hypertension is a general consequence of ethanol withdrawal, we have monitored blood pressure and heart rate in conscious rats during ethanol withdrawal. Sprague-Dawley rats were placed in Plexiglas chambers and exposed for 3 weeks to either ethanol vapor in air or to air alone.