In the sympathetic nervous system, what neurotransmitter is released by pre ganglionic neurons?

In the sympathetic nervous system, the neurotransmitter released by pre-ganglionic neurons is acetylcholine. This is due to the fact that pre-ganglionic neurons, which originate in the spinal cord, release acetylcholine at their synapses with post-ganglionic neurons in the sympathetic ganglia. Acetylcholine binds to nicotinic receptors on the post-ganglionic neurons, facilitating the transmission of signals that enable various sympathetic effects such as increased heart rate and dilated pupils during the fight-or-flight response.

This role of acetylcholine is foundational within the autonomic nervous system, serving as the first neurotransmitter in the sympathetic pathway before the post-ganglionic neurons release norepinephrine to affect organs and tissues. Understanding this connection is crucial for comprehending how the sympathetic nervous system orchestrates responses to stress and emergency situations.