Lee, E., Oliveira-Ferreira, A.I., de Water, E., Gerritsen, H.,
Bakker, M.C., Kalwij, J.A.W., van Goudoever, T.,
Buster, W.H. & Pennartz, C.M.A. (2009).
Ensemble recordings in awake rats: achieving behavioral regularity during
multimodal stimulus processing and discriminative learning.
Journal of the Experimental Analysis of Behavior, 92, 113-129.
To meet an increasing need to examine the neurophysiological underpinnings of
behavior in rats, we developed a behavioral system for studying sensory processing,
attention and discrimination learning in rats while recording firing patterns of
neurons in one or more brain areas of interest. Because neuronal activity is
sensitive to variations in behavior which may confound the identification of
neural correlates, a specific aim of the study was to allow rats to sample
sensory stimuli under conditions of strong behavioral regularity. Our behavioral
system allows multimodal stimulus presentation and is coupled to modules for
delivering reinforcement, simultaneous monitoring of behavior and recording
of ensembles of well isolated single neurons. Using training protocols for
simple and compound discrimination, we validated the behavioral system with
a group of 4 rats. Within these tasks, a majority of medial prefrontal
neurons showed significant firing-rate changes correlated to one or
more trial events that could not be explained from significant variation
in head position. Thus, ensemble recordings can be combined with
discriminative learning tasks under conditions of strong behavioral
regularity.
Key words: : attention, prefrontal cortex, electrode, single unit, spike,
olfactory, visual discrimination