Cataplexy-related neurons in the amygdala of the narcoleptic dog

Neuroscience. 2002;112(2):355-65. doi: 10.1016/s0306-4522(02)00089-1.


The amygdala plays an important role in the interpretation of emotionally significant stimuli and has strong projections to brainstem regions regulating muscle tone and sleep. Cataplexy, a symptom of narcolepsy, is a loss of muscle tone usually triggered by sudden, strong emotions. Extracellular single-unit recordings were carried out in the amygdala of narcoleptic dogs to test the hypothesis that abnormal activity of a subpopulation of amygdala neurons is linked to cataplexy. Of the 218 cells recorded, 31 were sleep active, 78 were active in both waking and rapid-eye-movement sleep, 88 were maximally active during waking, and 21 were state independent. Two populations of cells showed a significant change in activity with cataplexy. A population of sleep active cells localized to central and basal nucleus increased discharges prior to and during cataplexy. A population of wake active cells localized to the cortical nucleus decreased activity prior to and during cataplexy. We hypothesize that these cell populations have a role in mediation or modulation of cataplexy through interactions with meso-pontine regions controlling atonia. The anticholinesterase physostigmine, at doses which increased cataplexy, did not alter the activity of the cataplexy-related cells or of other amygdala cells, suggesting that its effect on cataplexy is mediated 'downstream' of the amygdala. The alpha-1 blocker prazosin, at doses which increased cataplexy, increased discharge in a subgroup of the cataplexy active cells and in a number of other amygdala cells, indicating that prazosin may modulate cataplexy by its action on amygdala cells or their afferents.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Action Potentials / drug effects
  • Adrenergic alpha-Antagonists / pharmacology
  • Amygdala / cytology
  • Amygdala / drug effects
  • Amygdala / physiopathology*
  • Animals
  • Cataplexy / physiopathology
  • Cerebral Cortex / physiology
  • Cerebral Cortex / physiopathology
  • Disease Models, Animal
  • Dogs
  • Electrodes, Implanted
  • Electroencephalography
  • Electromyography
  • Electrooculography
  • Hippocampus / physiology
  • Hippocampus / physiopathology
  • Muscle Tonus
  • Narcolepsy / physiopathology*
  • Neurons* / classification
  • Neurons* / drug effects
  • Neurons* / physiology
  • Prazosin / pharmacology
  • Sleep Stages / physiology
  • Wakefulness / physiology


  • Adrenergic alpha-Antagonists
  • Prazosin