18037
Cerebellar Stimulation Differentially Modulates Neuronal Activity in Mouse Prefrontal Cortex
Objectives: We investigated how electrical stimulation of the cerebellar cortex affects neuronal activity in frontal and prefrontal cortical areas in awake behaving mice.
Methods: We recorded local field potential (LPF) and single unit spike activity with up to five extracellular recording electrodes in the prelimbic, secondary motor and/or frontal association areas (Ant.-Post.: Bregma +2, Lat: 0.2 - 2.5 mm). Electrical stimulation (10 ms, 50 Hz, 100 µA, for 1.0 s) was applied with a bipolar electrode to the surface of the cerebellar hemisphere (Ant. Post.: -6.2, Lat.: 2 - 2.5 mm).
Results: At rest, the fluctuations of LFP activity were strongly correlated between recording sites and showed large, synchronized amplitude negative peaks at irregular intervals, which were associated with pauses in single unit spike activity across multiple recording sites. Cerebellar stimulation eliminated negative LFP peaks for a period of a few to tens of seconds, depending on stimulus amplitude. We analyzed the responses of 229 single units to cerebellar cortical stimulation. Firing rate increased in 73 (31.9%) and decreased in 28 (12.2%) units with 128 units (55.9%) showing no change in firing rate following cerebellar stimulation. Unilateral cerebellar stimulation affected PFC neuronal activity bilaterally.
Conclusions: Our findings show that increasing cerebellar cortical activity via electrical stimulation differentially modulates LFP and spiking activity in awake mouse PFC neurons, resulting in a temporary desynchronization of PFC network activity, an effect that might involve dopamine transmission (3).
References:
1. Middleton, Strick, J Neurosci 21, 700 (2001).
2. Krienen, Buckner, Cerebral Cortex 19, 2485 (2009).
3. Mittleman, et al. Synapse 62, 544 (2008).