GABA receptors in the posterior hypothalamus regulate experimental anxiety in rats

Anantha Shekhar, J. N. Hingtgen, J. A. DiMicco

Research output: Contribution to journalArticle

73 Citations (Scopus)

Abstract

Blockade of γ-aminobutyric acid (GABA) function in the posterior hypothalamus of rats elicits a pattern of physiological and behavioral arousal consisting of increases in heart rate, respiration and blood pressure as well as intense locomotor stimulation and a selective enhancement of avoidance responding. The present study was conducted to assess the possibility that GABA-mediated neurotransmission in the posterior hypothalamus of the rat may regulate anxiety. Male rats were trained in a 'conflict' schedule consisting of a high and a low intensity of punishment ('high' and 'low' conflict) capable of measuring decreases and increases in the level of 'anxiety', respectively. Guide cannulae were stereotaxically implanted bilaterally in the posterior hypothalamus of these rats at sites where microinjection of bicuculline methiodide (BMI) 25 ng caused increases in heart rate under anesthesia. After recovery, they were tested: (1) in the high conflict schedule after microinjection of saline and two doses of the GABAA receptor agonist muscimol; and (2) in the low conflict schedule after injecting saline, the GABAA receptor antagonists, BMI and picrotoxin, and the glycine antagonist, strychnine. Injection of muscimol caused a significant and selective anti-conflict effect while both BMI and, at appropriate doses, picrotoxin produced pro-conflict effects. Microinjection of strychnine into the posterior hypothalamus or muscimol and picrotoxin into the lateral hypothalamus did not influence conflict responding. These results suggest that endogenous GABA acts on GABAA receptors in a discrete area of the posterior hypothalamus to regulate the level of experimental anxiety in rats.

Original languageEnglish
Pages (from-to)81-88
Number of pages8
JournalBrain Research
Volume512
Issue number1
DOIs
StatePublished - Mar 26 1990

Fingerprint

Posterior Hypothalamus
GABA Receptors
Anxiety
Picrotoxin
Muscimol
Microinjections
gamma-Aminobutyric Acid
Strychnine
Appointments and Schedules
Heart Rate
Lateral Hypothalamic Area
GABA-A Receptor Agonists
Aminobutyrates
GABA-A Receptor Antagonists
Punishment
GABA-A Receptors
Conflict (Psychology)
Arousal
Synaptic Transmission
Glycine

Keywords

  • Anxiety
  • Bicuculline
  • Conflict
  • Hypothalamus
  • Muscimol
  • Picrotoxin
  • γ-Aminobutyric acid

ASJC Scopus subject areas

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

Cite this

GABA receptors in the posterior hypothalamus regulate experimental anxiety in rats. / Shekhar, Anantha; Hingtgen, J. N.; DiMicco, J. A.

In: Brain Research, Vol. 512, No. 1, 26.03.1990, p. 81-88.

Research output: Contribution to journalArticle

Shekhar, Anantha ; Hingtgen, J. N. ; DiMicco, J. A. / GABA receptors in the posterior hypothalamus regulate experimental anxiety in rats. In: Brain Research. 1990 ; Vol. 512, No. 1. pp. 81-88.
@article{93389daa1af0498dac20404913fc4251,
title = "GABA receptors in the posterior hypothalamus regulate experimental anxiety in rats",
abstract = "Blockade of γ-aminobutyric acid (GABA) function in the posterior hypothalamus of rats elicits a pattern of physiological and behavioral arousal consisting of increases in heart rate, respiration and blood pressure as well as intense locomotor stimulation and a selective enhancement of avoidance responding. The present study was conducted to assess the possibility that GABA-mediated neurotransmission in the posterior hypothalamus of the rat may regulate anxiety. Male rats were trained in a 'conflict' schedule consisting of a high and a low intensity of punishment ('high' and 'low' conflict) capable of measuring decreases and increases in the level of 'anxiety', respectively. Guide cannulae were stereotaxically implanted bilaterally in the posterior hypothalamus of these rats at sites where microinjection of bicuculline methiodide (BMI) 25 ng caused increases in heart rate under anesthesia. After recovery, they were tested: (1) in the high conflict schedule after microinjection of saline and two doses of the GABAA receptor agonist muscimol; and (2) in the low conflict schedule after injecting saline, the GABAA receptor antagonists, BMI and picrotoxin, and the glycine antagonist, strychnine. Injection of muscimol caused a significant and selective anti-conflict effect while both BMI and, at appropriate doses, picrotoxin produced pro-conflict effects. Microinjection of strychnine into the posterior hypothalamus or muscimol and picrotoxin into the lateral hypothalamus did not influence conflict responding. These results suggest that endogenous GABA acts on GABAA receptors in a discrete area of the posterior hypothalamus to regulate the level of experimental anxiety in rats.",
keywords = "Anxiety, Bicuculline, Conflict, Hypothalamus, Muscimol, Picrotoxin, γ-Aminobutyric acid",
author = "Anantha Shekhar and Hingtgen, {J. N.} and DiMicco, {J. A.}",
year = "1990",
month = "3",
day = "26",
doi = "10.1016/0006-8993(90)91173-E",
language = "English",
volume = "512",
pages = "81--88",
journal = "Brain Research",
issn = "0006-8993",
publisher = "Elsevier",
number = "1",

}

TY - JOUR

T1 - GABA receptors in the posterior hypothalamus regulate experimental anxiety in rats

AU - Shekhar, Anantha

AU - Hingtgen, J. N.

AU - DiMicco, J. A.

PY - 1990/3/26

Y1 - 1990/3/26

N2 - Blockade of γ-aminobutyric acid (GABA) function in the posterior hypothalamus of rats elicits a pattern of physiological and behavioral arousal consisting of increases in heart rate, respiration and blood pressure as well as intense locomotor stimulation and a selective enhancement of avoidance responding. The present study was conducted to assess the possibility that GABA-mediated neurotransmission in the posterior hypothalamus of the rat may regulate anxiety. Male rats were trained in a 'conflict' schedule consisting of a high and a low intensity of punishment ('high' and 'low' conflict) capable of measuring decreases and increases in the level of 'anxiety', respectively. Guide cannulae were stereotaxically implanted bilaterally in the posterior hypothalamus of these rats at sites where microinjection of bicuculline methiodide (BMI) 25 ng caused increases in heart rate under anesthesia. After recovery, they were tested: (1) in the high conflict schedule after microinjection of saline and two doses of the GABAA receptor agonist muscimol; and (2) in the low conflict schedule after injecting saline, the GABAA receptor antagonists, BMI and picrotoxin, and the glycine antagonist, strychnine. Injection of muscimol caused a significant and selective anti-conflict effect while both BMI and, at appropriate doses, picrotoxin produced pro-conflict effects. Microinjection of strychnine into the posterior hypothalamus or muscimol and picrotoxin into the lateral hypothalamus did not influence conflict responding. These results suggest that endogenous GABA acts on GABAA receptors in a discrete area of the posterior hypothalamus to regulate the level of experimental anxiety in rats.

AB - Blockade of γ-aminobutyric acid (GABA) function in the posterior hypothalamus of rats elicits a pattern of physiological and behavioral arousal consisting of increases in heart rate, respiration and blood pressure as well as intense locomotor stimulation and a selective enhancement of avoidance responding. The present study was conducted to assess the possibility that GABA-mediated neurotransmission in the posterior hypothalamus of the rat may regulate anxiety. Male rats were trained in a 'conflict' schedule consisting of a high and a low intensity of punishment ('high' and 'low' conflict) capable of measuring decreases and increases in the level of 'anxiety', respectively. Guide cannulae were stereotaxically implanted bilaterally in the posterior hypothalamus of these rats at sites where microinjection of bicuculline methiodide (BMI) 25 ng caused increases in heart rate under anesthesia. After recovery, they were tested: (1) in the high conflict schedule after microinjection of saline and two doses of the GABAA receptor agonist muscimol; and (2) in the low conflict schedule after injecting saline, the GABAA receptor antagonists, BMI and picrotoxin, and the glycine antagonist, strychnine. Injection of muscimol caused a significant and selective anti-conflict effect while both BMI and, at appropriate doses, picrotoxin produced pro-conflict effects. Microinjection of strychnine into the posterior hypothalamus or muscimol and picrotoxin into the lateral hypothalamus did not influence conflict responding. These results suggest that endogenous GABA acts on GABAA receptors in a discrete area of the posterior hypothalamus to regulate the level of experimental anxiety in rats.

KW - Anxiety

KW - Bicuculline

KW - Conflict

KW - Hypothalamus

KW - Muscimol

KW - Picrotoxin

KW - γ-Aminobutyric acid

UR - http://www.scopus.com/inward/record.url?scp=0025308530&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0025308530&partnerID=8YFLogxK

U2 - 10.1016/0006-8993(90)91173-E

DO - 10.1016/0006-8993(90)91173-E

M3 - Article

VL - 512

SP - 81

EP - 88

JO - Brain Research

JF - Brain Research

SN - 0006-8993

IS - 1

ER -