celulele din creier 2 Flashcards
What are the 2 types of receptors?
Ionotropic
Metabotropic
What is the role of acetylcholine?
The depolarise the receptive membrane turning it from negative to positive - excitatory pstsynaptic potential
Inhibitory postsynaptic potentials
Some neurotransmitters cause the postsynaptic membrane to hyperpolarise so that the inside becomes even more negative compared to the outside
GABA causes negatively charged chloride ions to enter postsynaptic neurones
Axon
All or none law (threshold)
Refractory period
Myelin can be present
Carry information from the soma
Active conduction
-no Inhibitory or Excitatory potentials
-no graded
-no degradation
Grey and white matter
Dendrite
Graded potential (no threshold)
No refractory period
No myelin
Carry information up to the axon hillock
Passive conduction
- Inhibitory or Excitatory potentials
- Graded
- Degradation
Grey matter
Acetylcholinesterase inhibitors
Found naturally in some venoms and poisons
Used to treat some conditions
What is acetylcholine?
Excitatory neurotrasmitter that triggers muscle contraction and stimulates the excretion of certain hormones
In the CNS it is involved in wakefulness, attentiveness, anger, aggression, sexuality and thirst
Alzheimer’s disease is associated with reduced acetylcholine in certain regions of the brain
What is dopamine?
A neurotransmitter involved in
controlling movement, posture and a range of higher-order cognitive functions.
It modulates mood and plays a
central role in positive reinforcement and dependency.
The loss of dopamine in certain
parts of the brain causes the muscle rigidity typical of Parkinson’s disease.
What is GABA?
Inhibitory neurotrasmitter widely distributed in the neurones of the cortex
Contributes to motor control, vision, and many
other cortical functions.
It plays an important role in regulating anxiety.
Some drugs that increase the level of GABA in
the brain are used to treat epilepsy and to
calm the trembling of people suffering from
Huntington’s disease
What is glutamate?
- Associated with learning, memory, visual awareness
- Crucial in Basal ganglia functioning
(modulation of motor activity) - Plays an important role in seizure activity.
What is serotonin?
- Contributes to various functions, such as regulating body
temperature, sleep, mood, appetite, and pain. - Depression, impulsive behaviour and general aggressiveness all
appear to involve imbalances in
serotonin.