All neuromodulators like dopamine, serotonin, acetylcholine, histamine, and norepinephrine act only on metabotropic receptors?

Is the concept of backpropagation in neural networks a phenomena actually observed in the brain?

This question is about the apparent activations revealed by two contrasts in neuroimaging using cognitive subtraction. Suppose we are comparing activations in the two tasks: reading words - single letters. This reveals greater activation in brain areas A, B & C, and deactivations in D,E & F. W...

Could the expression of a gene inside a neuron cause this neuron to fire spontaneously, i.e. without external stimuli?