Generating Local Cornu Ammonis 1 (CA1) Gamma Oscillations Using Tetanic Stimulations in a Hippocampal Brain Slice

Secure a brain slice in a recording chamber with a continuous perfusion of aCSF containing high magnesium that blocks N-methyl-D-aspartate or NMDA glutamate receptors.

Position the stimulating and recording electrodes in the hippocampal Cornu ammonis 1 or CA1 stratum radiatum.

Stimulate to obtain an electrical signal, confirming intact neuronal connections.

Reposition the stimulating electrode to the stratum oriens and the recording electrode to the stratum pyramidale, then insert them deeper.

Apply tetanic stimulations, high-frequency electrical pulses to induce excitatory neurotransmitter glutamate release from Schaffer collateral axons.

Glutamate binds to glutamate receptors on CA1 neurons, facilitating sodium influx and membrane depolarization.

This unblocks NMDA receptors, allowing sodium and calcium influx and enhancing neuron excitation.

The excited interneurons in the stratum oriens release the inhibitory neurotransmitter GABA, interacting with CA1 neurons.

This balance of excitatory and inhibitory inputs leads to synchronized controlled excitation of the CA1 neuronal network, generating rhythmic brain waves called gamma oscillations, crucial for attention and memory.