Intro to CNS Flashcards
1
Q
What is the brain?
A
- Input-output device
- Sensory info is processed and responded to
- 100 billion neurons, 100 billion glia, trillions of synapses
2
Q
What is Glutamate?
A
- Main excitatory transmitter
3
Q
What is GABA?
A
- Main inhibitory transmitter
4
Q
What are regional microcircuits?
A
- Straightforward circuit focussed on Purkinje cells
- 2 excitatory inputs:
- ~175,000 parallel fibres
- 1 climbing fibre
- Inhibitory interneurones feed forwards and backwards (Golgi, Basket and Stellate cells)
- Strength of connections can be modulated–Synaptic plasticity
5
Q
What is regional specialisation?
A
- Broad brush association of behavioural phenomena with substructures
- Amygdala–FEAR
- Cerebellum–Motor co-ordination
- Prefrontal cortex–Executive control
6
Q
What are Neuromodulatory transmitters?
A
- Long-distance projections that overlay synaptic network
- Volume transmission mechanism
- Distributed inputs that modulate microcircuits
7
Q
Give some examples of modulatory transmitters?
A
- Dopamine
- 5-HT
- Noradrenaline
- Acetylcholine
- Histamine
ETC
8
Q
What are consequences of neuromodulation?
A
- Inc or Dec excitatability
- Inc or Dec synaptic release probability
- After sensitivity to synaptic plasticity –Metaplasticity
- Modulate gene expression
- Shape dev, connectivity and computational properties or neuronal networks
9
Q
Explain complexity of the brain/NTs
A
- All neuromodulators play multiple roles
- Reflects widespread inf
- Extensive crosstalk and interconnectivity
- Makes targeted interventions difficult
10
Q
What is selectivity?
A
Receptor subtypes and reuptake transporters selectivtly expressed
* Coupled to different 2nd messenger signalling pathways
* Diff effects on neuronal function
* Expressed on dif classes of neurons
* Density varies in dif brain regions
11
Q
What is Dopamine?
A
- Neuronal somata collected into 2 main brainstem regions
1. Ventral tegmental area
2. Substantia nigra - Also in Hypothalamus
- Project to multiple brain regions through 4 main pathways
1. Mesolimbic
2. Mesocortical
3. Nigrostriatal
4. Tuberoinfundibular
12
Q
Decribe the dopamine pathways
A
13
Q
What are the roles of dopamine?
A
- Reward
- Motivation
- Pleasure-seeking
- Salience
- Movt
- Attention
- Arousal
- etc
14
Q
What is 5-HT?
A
- Brainstem nuclei
1. Raphe nuclei - Widespread projections throughout brain and spinal cord
- Serotonergic pathway
15
Q
What are the roles of 5-HT?
A
- Mood regulation
- Cognition/perception
- Feeding behaviour
- Sexual behaviour
- Aggression
- Sleep regulation
- Temp regulation
- etc
