Blockade of GABAA receptors in the region of the anterior basolateral amygdala of rats elicits increases in heart rate and blood pressure

S. K. Sanders, Anantha Shekhar

Research output: Contribution to journalArticle

93 Citations (Scopus)

Abstract

Stimulation of the amygdala in rats is known to elicit increases in heart rate (HR) and blood pressure (BP) as well as locomotor activity associated with emotional arousal. The present study was conducted to localize and characterize the role of the GABA system of the amygdala in regulating these cardiovascular responses. Male Sprague-Dawley rats with arterial chateters placed for physiological measurements were implanted with chronic microinjection cannulae in the anterior basolateral (BLA) and central (Ce) amygdaloid nuclei under pentobarbital anesthesia. After recovering, rats were microinjected bilaterally with saline (250 nl) and bicuculline methiodide (BMI, 5-25 ng/250 nl), a selective GABAA antagonist. Microinjection of BMI in the BLA caused significant increases in HR and BP as well as locomotor stimulation while saline had no effect. The cardiovascular response to BMI was blocked by pentobarbital anesthesia. Microinjection of equimolar concentrations of (+)-baclofen HCl (GABAB agonist), phaclofen (GABAB antagonist), or strychnine (glycine antagonist) into the BLA or BMI into the Ce had no significant cardiovascular effects. The cardiovascular effects of BMI injection in the BLA does not appear to be secondary to generalized seizure activity. These results suggest that endogenous GABA, acting on GABAA receptors in the region of the BLA, may be involved in cardiovascular regulation.

Original languageEnglish
Pages (from-to)101-110
Number of pages10
JournalBrain Research
Volume567
Issue number1
DOIs
StatePublished - Dec 13 1991

Fingerprint

Microinjections
GABA-A Receptors
Heart Rate
Pentobarbital
Blood Pressure
Amygdala
gamma-Aminobutyric Acid
Anesthesia
GABA-A Receptor Antagonists
Strychnine
Baclofen
Locomotion
Arousal
Glycine
Sprague Dawley Rats
Seizures
Injections
Basolateral Nuclear Complex

ASJC Scopus subject areas

  • Developmental Biology
  • Molecular Biology
  • Clinical Neurology
  • Neuroscience(all)

Cite this

Blockade of GABAA receptors in the region of the anterior basolateral amygdala of rats elicits increases in heart rate and blood pressure. / Sanders, S. K.; Shekhar, Anantha.

In: Brain Research, Vol. 567, No. 1, 13.12.1991, p. 101-110.

Research output: Contribution to journalArticle

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