Question

where you would find dendritic spines and what their role is in neuronal communication?

Answer 1

"A dendritic spine (or spine) is a small membranous protrusion from a neuron's dendrite that typically receives input from a single synapse of an axon. Dendritic spines serve as a storage site for synaptic strength and help transmit electrical signals to the neuron's cell body."

From wikipedia, hope it helps