Noradrenergic-dependent modulation of prefrontal cells activity in awake rats

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

Congreso; XXVIII Congreso anual de la Sociedad Argentina de Investigación en Neurociencias; 2013

The prefrontal cortex (PFC) is a region within frontal cortex formed by a network of neurons connected to virtually all sensory and motor systems and some subcortical systems. One of the main functions of this cortex is to ?along with other brain structures- organize behaviour in time, i.e. executive functioning. Attention, planning, task switching, decision making, are examples of executive functions that together determine the sequential organization of behaviour. The locus coeruleus (LC) is a noradrenergic brainstem structure and the sole source of noradrenaline (NA) to the neocortex. One of its functions is to regulate waking and arousal by changing the level and mode of LC activity. During focused attention, LC cells exhibit phasic activation for target stimuli and a moderate level of tonic discharge whereas in inattentive states there is a very low level LC activity in general. To further understand the role of the PFC in learning and decision making, single cell activity was recorded in awake rats, using a head restrained paradigm previously developed by our group. Local administration of drugs at the PFC was made through a novel arrangement of a glass electrode attached to the two wire-hexodes responsible for activity recording. In this work we show how the activity of PFC neurons is affected under local delivery of yohimbine, a α2A noradrenergic receptor antagonist, whose action resembles the effect of a reduction of noradrenaline release in an attentional state.