Noradrenergic networks in the anesthetized rat: Interaction between the locus coeruleus and the prefrontal cortex

ANABEL M.M. MIGUELEZ FERNÁNDEZ; CAMILO J. MININNI; B. SILVANO ZANUTTO

Washington DC

Congreso; Annual Meeting of the Society for Neuroscience; 2011

The locus coeruleus (LC) is a brainstem neuromodulatory nucleus and the sole source of noradrenaline to the cerebral, cerebellar, and hippocampal cortices. Although it’s role in complex and specific mechanisms of behavioural control has been widely investigated, little is known about the dynamics of interaction between LC and cortical neuron populations. Here we studied this interaction, analysing the temporal correlation of neurons firing. Ten extracellular electrophysiological recordings were made simultaneously in the Prefrontal Cortex (PFC) and the LC of anesthetized rats. Over fifty independent records were obtained, and after spike sorting analysis 365 neurons were identified: 134 from PFC and 231 from LC. Correlation analysis was performed pairwise between PFC and LC neurons finding positive interactions in short (1ms), medium (200ms) and long (3000ms) time scales. We found a tendency towards joint firing, and found neuron pairs interacted mostly in short and medium scales. Interactions found in the different time scales usually vary but in some cases the positive correlation persisted throughout the three scales. Cross-correlation analysis revealed interactions change, and they do so in different ways. Some neurons presented synchronous oscillating activity pattern where CPF and LC firing is approximately 200ms apart, being LC neuron population the first to fire most of the times.