The cholinergic basal forebrain in the ferret and its inputs to the auditory cortex.
Bottom Line: Epipial tracer deposits and injections of the immunotoxin ME20.4-SAP (monoclonal antibody specific for the p75 neurotrophin receptor conjugated to saporin) in the auditory cortex showed that cholinergic inputs originate almost exclusively in the ipsilateral nucleus basalis.Moreover, tracer injections in the nucleus basalis revealed a pattern of labelled fibres and terminal fields that resembled acetylcholinesterase fibre staining in the auditory cortex, with the heaviest labelling in layers II/III and in the infragranular layers.The widespread distribution of cholinergic inputs from the nucleus basalis to both primary and higher level areas of the auditory cortex suggests that acetylcholine is likely to be involved in modulating many aspects of auditory processing.
Affiliation: Department of Physiology, Anatomy and Genetics, University of Oxford, Sherrington Building, Parks Road, Oxford, OX1 3PT, UK.Show MeSH
Related in: MedlinePlus
Mentions: Two approaches were used to investigate projections from the BF to the auditory cortex. First, different tracers were applied to the three regions of the EG where the auditory cortex in the ferret is located in order to retrogradely label cells in the BF (n = 3, Figs6 and 7). Second, multiple injections of the immunotoxin ME20.4-SAP were made in the EG (n = 1, Figs8 and 9) to eliminate cholinergic neurons in the BF that project to the auditory cortex. Both procedures were carried out unilaterally.
Affiliation: Department of Physiology, Anatomy and Genetics, University of Oxford, Sherrington Building, Parks Road, Oxford, OX1 3PT, UK.