Display Settings:

Format

Send to:

Choose Destination
See comment in PubMed Commons below
Neuroendocrinology. 1993 May;57(5):815-24.

Rapid neurophysiological effects of corticosterone on medullary neurons: relationship to stress-induced suppression of courtship clasping in an amphibian.

Author information

  • 1Department of Psychology, University of Wyoming, Laramie 82071.

Abstract

Courtship clasping of females by male roughskin newts (Taricha granulosa) is rapidly blocked by exposure to corticosterone (CORT). This behavioral effect appears to result from CORT binding to a receptor in neuronal membranes. The present study investigated effects of intraperitoneal CORT administration on neurophysiological properties of extracellularly recorded single medullary neurons in acutely prepared newts. CORT produced multiple neurophysiological effects that emerged within 3 min of injection and increased in magnitude during the next 20-30 min. Spontaneously active and sensory-responsive neurons showed a decline or cessation of firing concomitant with a loss of sensory responsiveness, especially to cloacal pressure, a clasp-facilitating stimulus in behaving newts. After CORT administration, reticulospinal neurons that were backfired (antidromically activated) by spinal cord stimulation, exhibited reduced antidromic action potential amplitude, slowed rates of spike generation and other indications of reduced excitability. Comparable effects of CORT were also evident in newts with a premedullary brainstem transection, indicating a direct hormone action on the caudal neuraxis. Dexamethasone (DEX), a glucocorticoid that binds poorly to the CORT membrane receptor and has little effect on clasping, had little or no direct neurophysiological effect, but DEX injection 30 min before CORT interfered with the neurophysiological action of CORT. The rapidity, time course and specificity to CORT of these neurophysiological effects are consistent with mediation through the CORT membrane receptor. In addition, the pattern and dose sensitivity of these neurophysiological actions plus their occurrence in the medulla, suggest that they could underlie the CORT effect on courtship clasping.

PMID:
8413818
[PubMed - indexed for MEDLINE]

LinkOut - more resources

Other Literature Sources

Molecular Biology Databases

PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Loading ...
    Write to the Help Desk