Neurotransmitters are chemical molecules, Produced by neurons, they are communication tools!
They send signals to other neurons, muscles, or glands,
Excitatory, inhibitory, modulatory commands!
While signals passing within your neurons are electrical,
Communication between neurons is chemical After job completion, neurotransmitters
can be degraded, Or diffuse from
the receptor concentration is faded. There may also be reuptake, wherein the molecule,
Is reabsorbed by the neuron that released it, cool!
Acetylcholine (ACh)
First to be discovered was ACh, or Acetylcholine, ACh helps run your body’s maintenance routine,
It contracts smooth muscles, an excitatory function
And slows your heart rate down, an inhibitory function,
Whether a neurotransmitter, inhibits or excites, Depends only on the target cell receptor types!
In skeletal muscle, ACh binds nicotinic receptors, But in the heart, ACh binds muscarinic receptors.
In the CNS, it’s in interneurons that it’s mostly found,
In Alzheimer’s disease, the brain’s ACh levels are down.
Dopamine Now onto the modulatory neurotransmitter dopamine,
Which runs the brain reward system, and is a catecholamine!
Cell bodies producing it are largely found in the midbrain,
The ventral tegmental area and substantia nigra are its domain.
Dopamine floods synapses when you get something good,
It modulates your thoughts, actions, and even your mood!
Dopamine also controls your posture and movement,
And it promotes wakefulness, so your time is well spent
Low levels in Parkinson’s is what make movements slow,
While high levels in schizophrenia make hallucinations show.
Norepinephrine
Norepinephrine is released from the adrenal medulla
It increases your heart rate but makes digestion slowa!
In the brain, it heightens arousal and so preps you for action,
So challenges or threats are met with the right reaction!
It’s the sympathetic nervous system’s main neurotransmitter,
It’s released by fear and stress, like from reading twitter!
It’s related to epinephrine, which makes the fight or flight response,
A neurotransmitter and a hormone which at adrenoreceptors docks.
Serotonin Serotonin is the brain’s
key monoamine neurotransmitter, Messages within your gut,
and to your brain it delivers! It is modulatory, making tweaks to your systems,
Of cognition, emotions, physiology, and metabolism.
It regulates mood, sleep, wakefulness, appetite, and aggression,
Circadian rhythms, body temp, and neuroendocrine function!
Low serotonin results in sleepiness, brain fog, and confusion.
And low levels are found in people with depression.
GABA
The main inhibitor, GABA, keeps neuron messages at bay,
Inhibiting continuation of signals down a neural pathway,
Preventing excess signalling, it keeps activity in check,
Because excessive activity would just result in a wreck!
GABA removes signal “noise” and supports sleep, Disrupting GABA signalling makes anxiety run deep.
GABA’s released from both axon terminals and dendrites
Allowing a fine-tuned response to the excitation it fights!
GABA is synthesized from glutamate despite
The fact that it’s inhibitory, while glutamate excites.
Glutamate (or Glutamic Acid) Glutamate is the brain’s most
abundant free amino acid, Activating neurons so
excitatory action is granted! NMDA and AMPA are two major glutamate receptors,
They are on the receiving neuron and act as collectors!
It aids learning by affecting synaptic plasticity, Hence updating the brain’s connectivity!
Oxytocin Oxytocin forms strong bonds of loyalty and trust,
Makes the bond between mother and child more robust,
It stimulates release of milk from mammary glands,
During birth, the uterus contracts on its commands!
Oxytocin’s made and released from the hypothalamus,
Via the pituitary gland to trigger body responses!
Nitric Oxide (NO)
Nitric oxide is made on demand, it is a soluble gas,
Not stored in synaptic vesicles, through membranes it can pass,
When released it acts directly on molecules inside the cell,
It’s involved in memory and learning from what we can tell!