Week 5 - CNS Drugs Introduction Flashcards
CNS acting drugs have a major ______/____ and ____ (psychological) importance
therapeutic/clinical, mental
CNS acting drugs can produce diverse pharmacological & psychological effects. List some examples
Relief of Pain
Induction to Anesthesia
Prevention of Epileptic Seizures
Treatment of Depression
Reduction of Anxiety
Special importance (humans): recreational uses addiction/overdose
(alcohol, tea and coffee, nicotine, cannabis, ecstasy, opioids, cocaine, amphetamines)
CNS agents are medicines that affect the ___
CNS
CNS drugs affect the brain’s ____ and _____ of neurotransmitters (NT)
use, output
Drugs speed up the production of ____
NT
Drugs slow down _______ of NTs
production
Drugs mimic ____
NTs
CNS Drugs: Types
The Nervous System (NS
divided into CNS and PNS
The Organization of Nervous System (NS
Autonomic Nervous System (ANS)
PSNS = rest and digest
Sympathetic = fight or flight
The BRAIN
A Nerve is formed of _______ tissue (______ plus blood _______)
nervous, neurons, vessels
Efferent nerve: nerves that conduct signals _____ the CNS along _____ neurons to their _______ muscles and glands
from, motor, target
Afferent nerve: carries nerve impulses _____ sensory receptors or sense organs ______ the CNS
from, toward
Mixed nerve: nerves that contain both _______ and _______ axons, and thus conduct both _______ sensory information and ______ muscle commands in the _____ bundle
afferent, efferent, incoming, outgoing, same
Spinal nerve: _____ nerve that carries ______, _______, and _____ signals between the spinal cord and the body
mixed, motor, sensory, autonomic
The building blocks of the CNS are two types of cells: ?
Neurons and Glial cells
Neurons are specialized nerve cells that can _______ and ____ chemical and electrical signals
receive, transmit
Glial cells or neuroglia: (support functions)?
Astrocytes
Oligodendrocytes (provide myelin for many axons)
Microglial cells
Ependymal cells
The structure of a neuron
Communication within neurons
How do Neurons Communicate?
The process is occurring via orchestrated chemical
(release of neurotransmitters) and electrical (alteration of
neuronal membrane potential) actions
Action potentials are ______ signals carried along neurons
electrical
Neurotransmitters: the chemical messengers released from ________ neurons so they can “talk” to neighboring cells
presynaptic
The Receptor on the _______ cell is for “hearing” the message
neighboring
Synapses are ______ that allow signals to ____.
junctions, pass
Chemical synapse:
* Ionotropic receptors (Ligand-gated ion proteins)
Metabotropic receptors (G-protein coupled proteins)
Electrical synapse:
* Gap junction proteins
Action potential (AP) (nerve impulse): the change in _____ potential associated with the
passage of an ____ ____ the membrane of a neuron
electrical, impulse, along
APs are ?
all-or-nothing (on-off switches)
APs are ____-directional (from the ____ to ____ _____)
one, body, axon terminal
Electrical signal happens when ?
the polarity across their plasma membrane changes
Membrane potential: the differences between ____ and _____ of the cell
inside, outside
Describe a resting potential
Describe an action potential
Voltage-gated ion channels
Changes in polarization occur when ?
ion channels in the membrane open or close,
altering the ability of particular types of ions to enter or exit the neuron
Positive potential is defined as?
Depolarization – the opening of channels that let Na+ rush into a neuron
The neuron sends electrical signal
Negative potential is defined as?
Hyperpolarization – the opening of channels that let negative ions flow in
Prevents the neuron from receiving another stimulus
Electrical and chemical synapses
How Do Neurons Communicate?
Neurotransmitters: Chemical Molecules in the CNS
Small Molecule Transmitters
The neuropeptides are made up of ?
three or more amino acids (larger in size)?
Substance P (__ aa): carries ____ signals and stimulates ____ (high in __)
11, pain, vomiting, VC
Neuropeptide Y: stimulates ___
eating
Endorphins & enkephalins?
inhibit pain
Steroids:
?androgens and estrogens
Dopamine: important in ?
addiction and pleasure-seeking; over-eating, movements, attention
and learning, low in Parkinson’s disease
Serotonin: (5-hydroxytryptamine, 5HT). Important for ?
Linked with?
sleep, appetite, temperature regulation,
mood, anxiety, pain, memory, aggression, and perception. Linked with depression
Acetylcholine: ____ and ___ contractions; blockage causes ____, low in ______
muscle, heart, paralysis, Alzheimer’s
Norepinephrine: involved in body’s ?
emergency response and behavioral processes. Released in
(Noradrenalin) stress, excitement. Helps brain work faster, lift our mood, makes us feel alert and focused?
GABA are _____ that keeps neural ______ under control. If disrupted: _____, ______. ____ and ____ boost the action of GABA, make you ____.
inhibitors, communication, seizure, epilepsy, Alcohol, valium, calm
Glycine are ______ that keeps neural communication under control. If disrupted:
seizure, epilepsy. Alcohol and valium boost the action of GABA, make you calm
inhibitors
Glutamate: major ______ NT in the CNS, ____ brain functioning, linked to many other pathways, ____ and _____?
excitatory, normal, learning, memory, Anxiety, PTS, OCD, mania, depression, psychosis, schizophrenia
Histamine: ( ______ and ), ?
brain, spinal cord, arousal, attention, feeding behavior, and memory
Substance P: implicated in ?
reproduction, social behaviors, appetite, arousal, pain,
reward, and learning and memory
Orexin: (like glutamate): _____ homeostasis. Animals lacking orexin system have ?
energy, narcolepsy and disrupted
sleep-wake pattern
The NT-receptor complex may directly regulate the membrane potential by ?
altering permeability of
the cell membrane through opening or closing specific ion channels
The NT-receptor complex may initiate a sequence of chemical reactions that ?
alter ion transport across
the membrane. Specific intracellular signal molecules are called second messengers
Receptors are the site of ?
action for exogenous DRUGS (usually G protein-coupled receptors, GPCRs
What is the function of the second messenger system?
sustains and amplifies the cellular response to DRUG-RECEPTOR binding?
Neutrotransmitter: Receptor Functions
Functions:
* Excitatory PostSynaptic Potentials (EPSP, depolarization leading to action potential)
* Inhibitory PostSynaptic Potentials (IPSP, hyperpolarization leading to the “rest” potential)
Examples of neurotransmitters
Glutamate is the main excitatory transmitter in the CNS
* GABA is the main inhibitory NT in the adult vertebrate brain
* Glycine is the main inhibitory NT in the spinal cord
Whether the effect of a certain NT is excitatory or inhibitory at a given synapse
depends on ?
which of its receptor(s) are present on the postsynaptic (target) cell.?
Excitatory?
- Glutamate
- Aspartate
Inhibitory
- GABA
- Glycine
Mixed?
- Acetylcholine (Ach)
- Norepinephrine (NE)
- Epinephrine (EP)
- Dopamine (D)
- Serotonin (5-HT)
Neurotransmitter - Receptor Functions
Glutamate, GABA, Acetylcholine, Dopamine, Serotonin
Neurotransmitter - Receptor Functions
Glutamate, GABA, Acetylcholine, Dopamine, Serotonin
Acetylcholine - Excitatory
Acetylcholine - Inhibitory
CPCRs are?
main targets of existing drugs (30-50-% drugs bind to them)
GPCRs detect molecules ____ the cells and ____ cellular responses
outside, activate
GPCRs regulate ?
sensory (taste, light, smell) and non-sensory (neurological and endocrine) signals
______ comprise the largest family of transmembrane receptors (~ 1000 in humans)
GPCRs
GPCRs are ?
7 transmembrane helixes (7-transmembrane receptors, 7TM- R)
Describe the structure of GPCRs:
7 transmembrane alpha helixes receptors interact (coupled) with
trimetic signal-transducing G-proteins
G-proteins consist of α, β, and γ subunits
1) Each receptor binds to its ligand, 2) conformational changes
3) α separates from β and γ, 4) they interact with other proteins
5) 2nd messengers (cAMP) act on heart, muscle, vessels
