This is an historical archive of the activities of the MRC Anatomical Neuropharmacology Unit (MRC ANU) that operated at the University of Oxford from 1985 until March 2015. The MRC ANU established a reputation for world-leading research on the brain, for training new generations of scientists, and for engaging the general public in neuroscience. The successes of the MRC ANU are now built upon at the MRC Brain Network Dynamics Unit at the University of Oxford.

GABAergic action on dendrites in sleep and movement

Neuropeptides and GABA are co-expressed and co-released by hippocampal interneurons. Bistratified and O-LM cells innervate segregated dendritic domains of pyramidal cells and co-release GABA and somatostatin acting on pre- and postsynaptic receptors. How do the activity patterns of these peptidergic/GABAergic interneurons support behaviour? Katona et al. recorded, labelled and identified individual interneurons in freely-moving rats and investigated their firing activity during movement and sleep in relation to hippocampal network oscillations. They found that behavioural and network states differentiate the firing of somatostatin-expressing bistratified and O-LM interneurons in the hippocampus. During movement, the two cell types cooperate temporally, firing at the trough of theta oscillatory cycles but at different frequencies. In contrast, during sleep, the two cell types dissociate in their function; bistratified cells are strongly active while O-LM cells decrease firing.

The results suggest that segregated glutamatergic inputs to CA1 pyramidal cell dendrites from the entorhinal cortex and the CA3 area are differentially modulated by GABA and somatostatin during behaviour.