Daily changes in the mouse cingulate cortex responsivity to neurotransmitters and depolarizing medium: an...

Area of Science:

• Neuroscience
• Chronobiology
• Cellular Electrophysiology

Background:

• The cingulate cortex plays a crucial role in cognitive and emotional processing.
• Neuronal excitability and response patterns can be influenced by various factors, including time of day.
• Understanding daily variations in neuronal function is essential for interpreting experimental results and for understanding neurological disorders.

Purpose of the Study:

• To investigate daily variations in the reactivity of mouse cingulate cortex neurons.
• To determine if the time of day affects neuronal responses to neurotransmitters and depolarizing stimuli in vitro.
• To explore the presence of day-night modulation in neuronal excitability.

Main Methods:

• In vitro electrophysiological recordings from mouse cingulate cortex slices.
• Application of neurotransmitters (glutamate, GABA, acetylcholine) to evoke neuronal responses.
• Assessment of spontaneous neuronal activity and evoked responses.
• Comparison of neuronal reactivity in slices prepared at different times of the day (morning vs. evening).

Main Results:

• Glutamate-evoked excitation and GABA-evoked inhibition exhibited longer-lasting after-effects in evening-prepared slices.
• Acetylcholine application showed a higher incidence of excitatory responses in evening-prepared slices.
• Responses to a depolarizing medium were predominantly inhibitory in the evening, contrasting with a balanced excitation/inhibition ratio in the morning.

Conclusions:

• Neuronal reactivity in the mouse cingulate cortex is subject to day-night modulation.
• Significant daily changes in neuronal responses to neurotransmitters and depolarizing stimuli were observed in vitro.
• These findings highlight the importance of considering circadian rhythms in neurophysiological research and understanding brain function.