| LTD Induction in Adult Visual Cortex: Role of Stimulus Timing and Inhibition (2007) | |||||||||||||||
Abstract | |||||||||||||||
| One Hertz stimulation of afferents for 15 min with constant interstimulus intervals (regular stimulation) can induce longterm depression (LTD) of synaptic strength in the neocortex. However, it is unknown whether natural patterns of lowfrequency afferent spike activity induce LTD. Although neurons in the neocortex can fire at overall rates as low as 1 Hz, the intervals between spikes are irregular. This irregular spike activity (and thus, presumably, irregular activation of the synapses of that neuron onto postsynaptic targets) can be approximated by stimulation with Poisson-distributed interstimulus intervals (Poisson stimulation). Therefore, if low-frequency presynaptic spike activity in the intact neocortex is sufficient to induce a generalized LTD of synaptic transmission, then Poisson stimulation, which mimics this spike activity, should induce LTD in slices. We tested this hypothesis by comparing changes in the strength of synapses onto layer 2/3 pyramidal cells induced by The alteration of synaptic strengths by patterns of neuronal activity is thought to be a mechanism via which information is stored in the CNS. The ability to experimentally induce longterm potentiation (LTP) and long-term depression (LTD) in many different regions of the brain lends support to this hypothesis | |||||||||||||||
Publication details | |||||||||||||||
| |||||||||||||||