Hypoalgesia in Response to Sensitization During Acute Noise Stress

    loading  Checking for direct PDF access through Ovid

Abstract

Three experiments examined the antinociceptive response shown by rats during exposure to loud noise. Noise exposure resulted in a time-dependent elevation of radiant heat tail flick latency that varied as a function of stimulus intensity. Noise stress hypoalgesia in response to a 90-dB stimulus was blocked by pretreatment with the opioid antagonist naltrexone (0.1–7.0 mg/kg). Systemic administration of midazolam (2 mg/kg) prior to exposure to the stressor attenuated the elevation in tail flick latency. Because topographically similar antinociceptive responses may be elicited with a low intensity noise stimulus that has served as a Pavlovian conditional stimulus for shock, the use of this paradigm may permit direct comparisons of associative and nonassociative fear responses using qualitatively similar auditory stimuli.

Related Topics

    loading  Loading Related Articles