Psychopharmacology Chapter 1

Where does the synthesis of acetylcholine occur?

Terminal Button

Dopamine, Nore, and Ep

key excitatory Nt's

5 dopamine receptors

D1 and D5 are excitatory → D2,3,4 are inhibitory

Dopamine Receptor Locations

Name the 2 dopamine excitatory receptor locations

D1 and D5

Name the 3 dopamine inhibitatory receptor locations

D2,3,4

D1 location

Smooth muscles of pulmonary artery, kidney, smooth muscles of various organs

D2 location

Brain,, substantia nigra, neostriatal pathway, pulmonary artery, kidney

D3,4,5

Primary in the brain

Epinephrine Synthesis

Tyrosine → Dopa → Dopamine → Nore → Epine

Which NT's does reuptake occur in?

dopamine, serotonin, norepinephrine, epine, and glutamate

Modulates the release of many NTs including glutamate, GABA, dopamine etc.

Serotonin

Anatomical Neurotransmission

The connection between neurons at the synapse.

Anatomically neurons are hard wired and interconnected --> one direction communication

Chemical Neurotransmission

How chemical signals are coded, decoded, transduced and sent along the way

The Neurotransmission process

1. Stimulation of a presynaptic cell

2. This causes hormones, or nerve impulses

3. Impulses are converted to chemical messengers

4. Messengers are released to stimulate the receptors on the postsynaptic neuron

5. Communication inside the neuron is electrical and between neuron is chemical

Classic Retrograde Volume

With classic Neurotransmission communication begins with an electrical impulse that reaches the axon and triggers the release of a chemcial that is sent to the postsynaptic neuron

Signal Transduction Cascades

Strings of chemcial messages-contribute to gene expression-multiple messengers in this process

4 major types: G protein → Ion channel → hormone → Neurotrophin

Messenger #1 (A NT) → Messenger #2 (chemical 2nd messenger) → Messenger #3 (enzyme) → Messenger #4 (phosphate group

4 types of chemical messages/signal transduction

G-protein, Ion channel, hormone, Neurotrophin

Role of a first messenger

Bind to a ligand --> ligand conforms in the receptor

Role of second messengers

Play a role in → Proliferation, Differentiation, Migration, Survival, Apoptosis

They are the trigger of intracellular signal transduction cascades

Popular secondary messengers

cAMP

gAMP

Calcium

role of 4th messengers

Change the synthesis of neurotransmitters, alter neurotransmitter release, change the conductance of ions, and maintain the neuron's readiness to fire or dormancy

Neurotransmitters

1st messenger system-

• 2nd messenger system is activated-g-proteins/cAMP

• 3rd messenger system is activated-protein kinase

• 4th messenger system is activated-phosphorylates and attaches phosphates

• Gene activation—genes make proteins that have other effects

• Phosphorylation reactions continue short and long term—each step in the cascade further

amplifies the signal

Genes two regions

Cell nucleus & Coding regions

Early genes

On occasion a gene can be activated early, that is by the 3rd or

4th messenger and then activate the 5th (protein messenger)

Late Genes

When proteins are activated in early genes they can collaborate

and activate additional messenger transcription proteins so the early gene

activates the late gene

What is neurotransmission?

The process where neurotransmitters (NTs) are released in the synaptic cleft and exert their effects.

What are the major steps in neurotransmitter processing?

Synthesis, Storage, Release, Reception, Inactivation.

Where is acetylcholine primarily concentrated?

At the neuromuscular junction.

What role does acetylcholine play in the body?

It activates muscles and is involved in learning and memory.

What disease is associated with the loss of acetylcholine?

Alzheimer's disease.

What enzyme helps in the synthesis of acetylcholine?

Choline acetyltransferase (CHAT).

What enzyme breaks down acetylcholine?

Acetylcholinesterase.

What are the two types of acetylcholine receptors?

Nicotinic receptors and muscarinic receptors.

What neurotransmitters are classified as monoamine catecholamines?

Dopamine, norepinephrine, and epinephrine.

What physiological functions do catecholamines control?

They control most other systems and physiological functions in the body.

What is dopamine involved in?

Pleasure, rewards, attention, and movement.

Where is dopamine synthesized?

In the midbrain.

What is the role of monoamine oxidase in dopamine processing?

It is involved in the deactivation of dopamine.

What are the two types of norepinephrine receptors?

Alpha and beta receptors.

What is epinephrine also known as?

Adrenaline.

What is the precursor for serotonin?

Tryptophan.

What effects does serotonin have?

It influences mood, sleep, and has psychedelic effects.

What is the primary function of glutamate?

It is an excitatory amino acid neurotransmitter that excites cells.

What is the role of GABA in neurotransmission?

It is an inhibitory amino acid neurotransmitter that inhibits neuron activity.

What is the classic neurotransmission process?

Stimulation of a presynaptic cell, conversion of impulses to chemical messengers, release to postsynaptic receptors.

What is retrograde neurotransmission?

Communication where postsynaptic neurons can send signals back to presynaptic neurons.

What are the three retrograde neurotransmitters mentioned?

Cannabinoids, nitric oxide, and nerve growth factor.

What is volume transmission?

A process where chemical messengers spill over to other sites via diffusion, not requiring a synapse.

What is excitation-secretion coupling?

The conversion of an electrical impulse on the presynaptic neuron to a chemical signal at the synapse.

What are first messengers in neurotransmission?

Neurotransmitters and hormones.

What role do second messengers play?

They trigger intracellular signal transduction cascades affecting various cellular processes.

What is the process of gene activation in neurons?

A transcription factor binds to the regulatory region of a gene, activating it and leading to protein synthesis.

What is epigenetics in the context of neurotransmission?

The study of which genes are turned on or silenced, affecting neuron function and mental health.