Lecture Notes Review - Psychopharmacology and Neurotransmitters

Announcements

• Research Participation:

  • Target Group: 1st generation immigrant students.
  • Objective: Interview about student experiences to improve psychosocial supports in higher education.
  • Criteria: Permanent residents in Canada (including refugees), immigrated after age 12, completed at least one semester at Bishop’s, and lived in Canada for at least one year.
  • Interview Duration: Approximately 1 hour.
  • Contact Person: Claude Charpentier (ccharpen@ubishops.ca).

• Clinical Case Study Challenge (BUUPS):

  • Date and Time: March 11th, 2025, from 6:00 PM to 9:00 PM.
  • Location: Adams Dining Room (Dewhurst).
  • Event Highlights:
  • Teams of four create a case study based on a given diagnosis.
  • Evaluation by a panel of three judges.
  • Public invited to attend the second half of the event.
  • Registration: Required.

Psychopharmacology

• Key Terms:

  • Affinity: Strength of binding between a ligand and its receptor.
  • Efficacy: Effectiveness of the ligand in activating the receptor.
  • Agonist vs. Antagonist:
  • Agonist: activates the receptor.
  • Antagonist: blocks the receptor.

• Neurotransmitter Functions:

  • Each neurotransmitter is associated with specific behaviors, has unique synthesis pathways, and interacts with distinct receptors.
  • Different routes of drug administration impact the speed and effectiveness of drug action.

• Pharmacokinetics vs. Pharmacodynamics:

  • Pharmacokinetics: Drug movement within the body (absorption, distribution, metabolism, excretion).
  • Pharmacodynamics: Effects of drugs on the body after absorption, particularly at receptor sites.

Pharmacodynamics

• Factors Influencing Drug Effects:

  • Site of Action: Receptor locations determine physiological and behavioral effects.
  • Affinity: Binding strength and duration of a ligand to its receptor.
  • Efficacy: How effectively a bound ligand alters the receptor's activity.

• Lock and Key Model:

  • Describes how ligands bind to receptors, enabling physiochemical changes in the target cell.

Drug Mechanisms of Action

• Stages of Drug Interaction:
  • Synthesis, Storage, Release, Receptor Interaction, Inactivation, Reuptake, and Degradation of neurotransmitters.

Neurotransmitters Overview

• Acetylcholine (ACh):

  • Involved in all muscle movements (somatic nervous system) and autonomic functions (both sympathetic and parasympathetic).
  • Degradation by acetylcholinesterase leads to recycling of choline and acetate.

• Catecholamines (Dopamine, Norepinephrine, Epinephrine):

  • Involved in arousal and motivational behaviors; synthesized in series from the precursor during stress responses.

• Dopamine (DA):

  • Functions in movement control and reward pathways; pathway disruptions can lead to disorders like Parkinson's Disease.

• Norepinephrine (NE):

  • Derives from the locus coeruleus, influences autonomic processing and arousal.

• Serotonin (5-HT):

  • Derives from tryptophan, key in mood, learning, and sleep regulation with multiple receptor subtypes.

Amino Acid Neurotransmitters

• Glutamate:

  • Most abundant excitatory neurotransmitter in the CNS; crucial for learning and memory processes.
  • Involved in synaptic plasticity, implicated in neurotoxicity under excessive stimulation.

• GABA (Gamma-Aminobutyric Acid):

  • Primary inhibitory neurotransmitter, key for controlling neuronal excitability throughout the nervous system.
  • Comes in two receptor types (ionotropic and metabotropic), mediating various physiological responses via chloride and potassium channels.