Sensory modality-specific homeostatic plasticity in the developing optic tectum.

We found a previously unknown form of homeostatic synaptic plasticity in multisensory neurons in the optic tectum of Xenopus laevis tadpoles. Individual tectal neurons are known to receive converging inputs from multiple sensory modalities. We observed that long-term alterations in either visual or mechanosensory activity in vivo resulted in homeostatic changes specific to each sensory modality. In contrast with typical forms of homeostatic synaptic plasticity, such as synaptic scaling, we found that this type of plasticity occurred in a pathway-specific manner that is more reminiscent of hebbian-type plasticity.