Hippocampal Micro-Circuitry

Comparison of avian and mammalian hippocampus – micro-circuitry

The avian and mammalian hippocampal formations are homologous, and are therefore both derived from the same ancestral brain structure. 300 million years of evolution have resulted in two very different-looking structures which nevertheless perform similar functions in memory and spatial navigation.

In this project, we explore whether, despite the different cyto-architecture, the micro-circuitry of the avian and mammalian hippocampal formations has been conserved, in order to perform the conserved functions. We focus in the first instance on the micro-circuits involved in generating hippocampal oscillations. These oscillations are believed to be important in organizing and synchronizing populations of neurons in processing information.

In our first studies, we have found that slices of the avian hippocampal formation can generate gamma oscillations (30-80Hz) in vitro, and that similar circuits seem to be involved in generating these oscillations as in mammals. We use local field potential recordings in 400-micron hippocampal slices, combined with pharmacological manipulation of different receptors and ion channels in order to dissect the micro-circuitry.

aviangammaFuture work may involve multi-electrode array recordings or patch clamp recordings to further characterize how individual neurons and populations of neurons contribute to the generation of these populations rhythms in birds.

This work has been done entirely as projects by students on the MRes in Neuroscience.


Mark Cunningham