Muscarinic dependence of nucleus basalis induced conditioned receptive field plasticity

Receptive field (RF) plasticity in primary auditory cortex of adult animals , specifically selective increased response to a tonal conditioned stimulus (CS) relative to other frequencies, can be induced both by behavioral cond itioning and by pairing a tone with stimulation of the nucleus basalis (NB) . This study determined whether cortical muscarinic receptors are necessary for NB-induced RF plasticity. Single units in layers II-IV were studied in Urethane anesthetized adult rats. The cortex was perfused with saline or s aline+atropine sulfate. Conditioning, 30 trials of pairing a tone with NB s timulation, produced a significant CS-specific response increase (n=8). Loc al atropine blocked NB-induced RF plasticity, actually resulting in CS-spec ific response decrease (n=6). Therefore, NB-induced RF plasticity requires engagement of muscarinic receptors in auditory colter. NeuroReport 12:1537- 1542 (C) 2001 Lippincott Williams & Wilkins.