Synapse PDF

The Synapse  Introduction to Neurons and Synapses Neurons are specialized cells that transmit information throughout the body A synapse is the connection point where neurons communicate Approximately 100 trillion synapses in the human brain Essential for learning, memo...

The Synapse  Introduction to Neurons and Synapses Neurons are specialized cells that transmit information throughout the body A synapse is the connection point where neurons communicate Approximately 100 trillion synapses in the human brain Essential for learning, memory, and all bodily functions  Types of Synapses Chemical synapses: Most common, uses neurotransmitters Electrical synapses: Direct communication through gap junctions Synaptic strength varies based on usage and importance Anatomy of a Synapse Presynaptic terminal: Contains neurotransmitter vesicles Synaptic cleft: Space between neurons (20-40 nanometers) Postsynaptic membrane: Contains receptor proteins Synaptic vesicles: Store and release neurotransmitters Thi s Photo by Unknown Author i s l icensed under CC BY  Synaptic Transmission Steps Action potential reaches presynaptic terminal Calcium channels open Vesicles release neurotransmitters Neurotransmitters bind to receptors Postsynaptic response generated (CCC’s open or close based on the type of neurotransmitter)  What are Neurotransmitters? Chemical messengers in the brain Released by presynaptic neurons Bind to specific receptors Different types produce various effects Can be excitatory (moves the membrane potential closer to threshold) or inhibitory (moves the membrane potential farther away from threshold)  Neurotransmitters Acetylcholine: Memory, muscle control Dopamine: Reward, pleasure, movement Serotonin: Mood, sleep, appetite GABA: Main inhibitory neurotransmitter Norepinephrine: Alertness, fight-or-flight Glutamate: Main excitatory neurotransmitter Endorphins: Natural pain relief Oxytocin: Social bonding, trust  Neurotransmitters and Depression Can be caused by: Serotonin imbalance Norepinephrine disruption Dopamine dysfunction Treatment often targets these systems  Anxiety Disorders and Neurotransmitters GABA deficiency Serotonin irregularities Norepinephrine imbalance Treatment approaches through medication  Parkinson's Disease Dopamine depletion due to loss of dopamine producing neurons at the base of the brain Affects movement control Progressive deterioration Treatment: L-DOPA and other medications  Schizophrenia Dopamine excess in some brain regions Glutamate abnormalities Complex neurotransmitter interactions Antipsychotic medications target these systems  How Medications Work Reuptake inhibition Receptor blocking Enzyme inhibition Neurotransmitter supplementation  Illegal Drugs and Synapses Cocaine: Blocks dopamine reuptake Heroin: Mimics endorphins Methamphetamine: Increases dopamine release MDMA: Affects serotonin systems  Drug Effects on the Brain Altered neurotransmitter levels Changed receptor sensitivity Potential permanent damage Addiction and dependency risks