BIOL 1F25 Lecture Notes - Mesolimbic Pathway, Nucleus Accumbens, C-Fos

• School: Brock University
• Department: Biological Sciences
• Course: BIOL 1F25
• Professor: John Mitterer

Document Summary

Last lecture: chronic administration of cocaine up regulates creb and increases dynorphon release from nacl impairs reward pathways. Produces decreased sensitivity to rewarding effects of subsequent drug exposure (tolerance) Role of fosb: transcription factor in nac c-fos induced in nac by acute cocaine use, but proteins are unstable and levels return to normal within 8-12 hours. Chronic cocaine induced a novel fob protein: fosb in nac very stable. Fosb induced in nac by many drugs of abuse and non-drug rewards. Because of stability of fosb may drive behavioural changes for weeks and months. Changes in fosb not long-lived enough to account for life-long addictions. Hypothesis: structural changes in neurons of reward pathway are responsible. Chronic cocaine use: increases # of dendrites of nac neurons persist for months. But- no current direct evidence that increased # of dendrites underlie long-lived behavioural changes. Analogous to learning and memory field difficult to associate cellular changes with behavioural changes.