Cerebral Neurochemical Mechanisms in Stress and Anxiety.
Abstract
Cerebral noradrenergic systems and their interactions with corticotropin-releasing factor (CRF) in stress-related responses were studied. (1) Microdialysis studies indicated that hypotension and footshock increased release of hypothalamic and cortical norepinephrine (NE). (2) A new voltammetric probe was designed to provide voltammetric data that a hypotensive agent, sodium nitroprusside, increases cortical NE secretion. (3) CRF infused into the locus coeruleus (LC) but not into surrounding structures, such as the parabrachial nucleus, increased secretion of cortical NE, supporting the notion that CRF affects the activity of LC-NE neurons. (4) Peripheral administration of interleukin-1 (IL-1) known to activate cerebral noradrenergic systems increased extracellular NE in the hypothalamus, and this activation was implicated in the induction of Fos protein in the hypothalamic paraventricular nucleus. (5) Chlordiazepoxide administered systemically or locally decreased the secretion of NE induced by footshock and CRF. (6) Activation of noradrenergic systems by idazoxan or treatment with propranolol attenuated footshock-induced freezing and ultrasonic vocalization. Idazoxan did not alter the acquisition of conditioned fear, but it depressed the expression of that behavior. (7) 6-Hydroxydopamine lesions of the dorsal noradrenergic bundle did not consistently alter stress-induced behavioral patterns.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 30, 1996
- Accession Number
- ADA320681
Entities
People
- Adrian J. Dunn
- Arthur H. Swiergiel
Organizations
- Louisiana State University