Question

compare and contrast signaling at electrical and chemical synapses

Answer 1

At an electrical synapse, action potentials (impulses) conduct directly between adjacent cells through structures called gap junctions. Gap junctions allow rapid communication between cells. No neurotransmitters are involved in an electrical synapse. As ions flow from one cell to the next through the gap junctions, the action potential spreads from cell to cell. In contrast to chemical synapses, chemical synpases transmit signals in both directions and have two main advantages: faster communication and synchronization.

In chemical synapses, the axon terminal of the presynaptic neuron, which conducts its action potential towards the synapse, ends in a swelling, the synaptic knob. The synaptic knob contains synaptic vesicles, which store a specific chemical messenger, a neurotransmitter that has been synthesized and packaged by the presynaptic neuron. There are many kinds of neurotransmitters, the best studied being acetylcholine Most chemical synapses operate in one direction only; that is, the presynaptic neuron brings about changes in the membrane potential of the postsynaptic neuron.