Theme 1: Fundamental Neuroscience and the Brain Flashcards
What are the 5 ways we study the brain?
Structure, Function, Connectivity, Trans-cranial Magnetic Stimulation/Temporary Lesion, Brain-Machine Interface
What are the 4 things a neuron must be able to do with neurotransmitters?
Synthesis, Storage, Release, Recovery and Degradation
Where can synapses be located?
Axodendritic, Axosomatic, Axoaxonic
What is the synaptic button?
a
What are the components of a chemical synapse?
Synaptic Button, Cytoskeleton, Mitochondria, Synaptic Vesicles, Active Zone, Synaptic Cleft
What is the Active Zone of a chemical synapse?
b
How large is the synaptic cleft?
20-50 nm wide
What does structure say about the synapse?
The presence of many mitochondria suggests the chemical synapse is a very energy hungry process needing a lot of ATP.
How do chemical signals get transmitted?
Vesicles fuse with postsynaptic membrane in synaptic cleft, releasing neurotransmitters into the postsynaptic neuron or muscle fibre (motor-end plate).
What can be the result of a synaptic transmission?
Direct excitatory (depolarised membrane) or inhibitory (hyperpolarised) neurotransmission, or Neuromodulation
What is Neuromodulation?
An alteration of the presynaptic cell’s ability to release more neurotransmitter or the postsynaptic cell’s ability to respond, usually by neurotransmitters
Name the 4 criteria defining a neurotransmitter
synthesized in neuron, present in presynaptic terminal and released in amounts sufficient to exert a defined effect on the postsynaptic neuron or effector organ, when administered exogenously mimics the action of the endogenously released transmitter, a specific mechanism exists for removing it from the synaptic cleft
What are the 2 categories of neurotransmitters?
Small-molecule neurotransmitters synthesized in the axon terminal (eg ACh) and larger Neuropeptides made in cell body.
What do the neural crest cells differentiate into?
(1) neurons and glia, (2)adrenal gland, (3) epidermis (4) skeletal and connective tissue of head
What are the layers of the neural tube?
lumen, ependymal layer, mantle layer, neural crest cells, ectoderm
What does the mantle layer of the neural tube become?
brain parenchyma
What does the ependymal layer of the neural tube do?
lines ventricles and central canal of spinal cord
What does the lumen of the neural tube become?
becomes ventricles and central canal
What are some neural tube defects?
Anencephaly 1 per thousand pregnancies (fatal failure of neural tube to zipper up at head), Spina Bifida 1 per thousand (25% morbidity, leads to open spinal canal)
What can help prevent neural tube defects?
Folic acid during pregnancy
What are the primary vesicles?
Prosencephalon (forebrain), mesencephalon (midbrain), rhombencephalon (hindbrain)
What are the secondary vesicles of the prosencephalon?
Telencephalon (cerebral hemispheres) and Optic Vesicles (eyes)
What are the secondary vesicles of the mesencephalon?
Diencephalon = thalamus/hypothalamus
What are the secondary vesicles of the rhombencephalon?
Metencephalon (pons and cerebellum) and Myelencephalon (medulla)
What does the mid-brain develop from?
mesencephalon
What are gray and white matter?
Gray matter is neuronal cell bodies (eg cerebral cortex, brain nuclei) and white matter is mainly myelinated axons.
What makes up the telencephalon?
Cerebral hemispheres/cerebral cortex, components of the limbic system, and the basal ganglia
Name the lobes of the cerebral hemispheres and their relative locations
Frontal (anterior), parietal (superior), occipital (posterior), temporal (lateral)
Name the major gyri and sulci and functions
Precentral gyrus (motor), postcentral gyrus (sensory), central sulcus (dividdes frontal and parietal lobes), lateral sulcus (divides temporal and parietal lobes),
List the sensory cortexes and locations
Somatosensory cortex (postcentral gyrus), visual cortex (occipital lobe), auditory, olfactory, gustatory cortexes (see diagram)
What is the white matter tract linking cerebral hemispheres?
Corpus Callosum
What are the parts of the corpus callousm?
Genu, Body, Splenium