Brains, neurons and neural coding Flashcards
name the most abundant type of neuron found in the brain
Pyramidal cells
name the parts of the human brain (including the lobes of the brain)
1)Frontal lobe
2)Temporal lobe
3)Parietal lobe
4)Occipital lobe
5)Spinal cord
6)Cerebellum
what are the 3 primary brain vesicles?
1) Forebrain
2)Midbrain
3)Hindbrain
what do we get from the 3 primary brain vesicles?
the 6 major divisions of the adult CNS
what are the 6 major divisions of the adult CNS?
1)Cerebrum
2)Thalamus and hypothalamus
3)Midbrain
4) Pons and cerebellum
5)Medulla
6)Spinal cord
Where is the forebrain located?, what are its basic functions once It develops?
Location= most front of the primary vesicles
Develops into structures associated with higher-order functions e.g. cognition, sensory perception and voluntary movement
what are the 2 subdivisions of the forebrain and what do they develop into?
1) Telencephalon= becomes cerebral cortex, basal ganglia and olfactory bulb
2)Diencephalon= gives rise to the thalamus, hypothalamus, epithalamus and sub thalamus
what is the midbrain involved in and what structures does it develop into?
Involved in functions e.g. vision, hearing, motor control and arousal.
The mesencephalon/midbrain develops into the adult midbrain, which includes structures like the tectum (visual and auditory reflexes) and tegmentum (motor control)
The hindbrain can be divided into 2 secondary vesicles. what are they and what structures do these secondary vesicles develop into?
1) Melencephalon = develops into cerebellum and pons
2) Myelencephalon= forms the medulla oblongata, which is involved in autonomic control (e.g. breathing and heart rate regulation)
define sensation
initial detection of external stimuli by the sensory organs- specialised sensory receptors convert these stimuli into electrical signals (AP) in the nervous system.
define perception
After detection of sensation the electrical signals are transmitted to the brain via the nervous system, resulting in interpretation
define neural processing
how the brain organises and processes these electrical signals from the sensory organs via neurons
define neural code
the way sensory info in represented and transmitted in the nervous system- how neurons communicate with each other
what are the 5 key components of the neural code?
1) Action potentials
2)Rate coding- rate of neural firing corresponds to the intensity of a stimulus
3) Temporal coding- timing of AP
4) Population coding- populations of neurons working together
5)Labelled-line coding= in some sensory systems, specific neurons or pathways are dedicated to certain types of stimuli
what are spikes another word for?
Action potentials
what are neural circuits?
Specific synaptic connections between nerve cells form circuits or networks
define rate code
the average spike frequency. Number of spikes over some integration of time
define temporal code
The precise timing of spikes within a spike train
define conduction
How fast an action potential travels along nerves
define generation
how quickly an action potential is generated
what are the 4 ways electrical activity of the nervous system can be recorded from lowest to highest resolution?
1) EEG
2) ECoG
3)Extracellular recording
4)Intracellular recording
What is an EEG (electroencephalography)?
- Non-invasive method to measure and record the electrical activity of the brain
-metal electrodes are placed on the scalp or an adhesive cap - electrodes detect tiny electrical changes resulting In neural activity beneath the skull
- Measures brain waves, oscillating electrical patterns due to synchronised neural activity
What is an ECoG?
-Similar to EEG but electrodes placed directly on cortical surface of the brain
- Records local field potentials due to summed neural activity, cannot resolve individual neural activity
what is an Extracellular recording?
Insulated electrodes inserted into cortical tissues and spikes are detected
what are intracellular recordings?
electode inserted into a single cell
What is Signal averaging:event related potentials (ERP)?
Random fluctuations cancel out whilst timed ones will be selected and averaged so the background (random) activity cancels out/flattens
