Fig. 6
From: Heterosynaptic plasticity-induced modulation of synapses
Homosynaptic and heterosynaptic changes in long-lasting plasticity. A All the required events for synaptic strengthening or weakening arise from the same synapse in homosynaptic plasticity. These alterations may cause an enhancement (homosynaptic facilitation) or a reduction in synaptic strength (homosynaptic depression). B The firing of a third neuron, a modulatory interneuron whose terminals end on the synapse, can adjust the strength of the specific synapse. These alterations may cause a rise (heterosynaptic, modulatory facilitation) or a decline (heterosynaptic inhibition) in synaptic strength (from Bailey et al. [77])