histochemistry Flashcards
Explain a bit about neurons and glia
1- Neurons are functional, signal conducting cells. Glia are supporting cells, synaptic transmission, homeostasis of microenvironment, immune surveillance.
Explain a bit about sensation.
Sensation: monitors changes/events occurring in and outside the body . such changes are known as stimuli and cells that monitor them are sensory neurons with receptors on their body surface and internally
Explain a bit about integration.
Integration: The parallel processing and interpretation of sensory information to determine the appropriate response.
Explain a bit about movement.
Movement: motor output. The activation of muscles or glands, typically via the release of neurotransmitters.
Give a bit of explanation about central nervous system.
Highly cellular. 85 billion neurons. 1000-10.000 synapsen /neuron
How does electrical information flow?
From the cell body tot he exon. The axon is the presynaptic neuron and the dendrites is the postsynaptic neuron.
Explain a bit about the soma/celbody.
This is where the dendrites are sticking out.(receiving information). In the nucleus there is DNA. Have high specialized rough endoplasmatic reticulum: complex of RNA & protein, stained by cresyl violet. In the soma you can find a lot mitochondria.
Explain a bit about dendrites.
These are the extensions from the soma (the receptive area)
Explain a bit about graded potentials.
Al kinds of signals from the dendrites go through the soma and only at the part just before the axon an action potential could be generated. Graded potentials could be excitatory postsynaptic potentials (EPSP) or inhibitory postsynaptic potentials. This will lead to the generation of an action potential or not.
Explain a bit about dendritic spines.
Very dynamic, they can change there shape. They can even change their existence. Increase after birth, decrease with age.
Where is the initiation of the action potential.
It is called the axon hillock.
Explain about sheated with myelin in consideration with swancells olidondendrocytes .
CNS: oligodendrocytes PNS: Schwann cells.
Explain a bit about Oligodendrocytes.
Oligodendrocytes:
* Produce myelin sheath: provide electrical insulation for many neurons in the CNS.
*one oligodendrocyte multiple exons & neurons
Explain a bit about astrocytes.
- Star-shaped, abundant, and versatile
- Guide the migration of development neurons.
- Act as k+ buffer and fine tuning of neurotransmitter release by mobilization of CA++ ions
- Involved in the formation of blood brain barrier
- Function in nutrient transfer.
Explain a bit about microglia.
- Monocyte/macrophage linage
- Immune cells of the CNS
- Antigen presenting cells
- Phagocytic cells
- Synapse removal/ remodelling
- Different phenotypes.
Explain a bit about ependymal cells.
- Columnar epithelial-like cells around the ventricles of the brain and the central canal of the spinal cord.
- Some are ciliated which facilitates the movement of the cerebrospinal fluid.
How much does the cerebral cortex weighs and what is the surface area?
The cerebral cortex is 80 % of the total brain weight in humans. The surface area of 2,5 feet in humans. Only 1/3 of the surface area visible, 2/3 in banks of sulci.
Explain a bit about golgi staining.
Golgi staining: random impregnation of limited number of cells give what type neurons, but does not colour all neurons.
Explain a bit about nissl staining.
Nissl staining; rough ER (nissle bodies) all neurons.
Explain a bit about weigert staining.
Stains myeling sheets (white matter) (not that important)
What is ganglion ?
Clusters of neurons in pns (e.g. dorsal root ganglia sympathetic ganglia.
What is nuclei
(kom hier later op terug)
ignore
Tell a bit about layers. Pyramidal cells, granule cells.
Pyramidal cells can be found in layer 2,3,5 and granule cells in layers 1 and 4.
Explain a bit about pyramidal cells.
pyramidal cells:
- large apical dendrite & basal dendrites.
- Axon projects downward into subcortical white matter.
- Primary output neuron.
explain a bit about granule cells
Granule cells (stellate cells)
- Short dendrites extending all directions.
- Short axon projecting to adjacent pyramidal cells.
- Especially numerous in sensory and associating cortex,
- Excitatory neurons.
explain a bit about GABAergic interneurons.
GABAergic neurons: (you need these interneurons to regulate the function of excitatory cells)
- 30 % of neurons in the cerebral cortex.
- Many different types
- Determine activity of excitatory granule & pyramidal cells.
Give some details about the layers of the cerebral cortex.
Layers cerebral cortex :
- Layer one lot of things there. Lot of exons, glia cells. Mainly receive input from cortical areas.
- Layer 4 has granual cells that have short connections. They receive a lot of information. They will send that to the bigger cells in the neighbourhood. To process information and than to give output outside of this network. (especially important when information comes in from the thalamus) mayor input being processed.
- Layer 5 has the large pyramidal cells with long projections so they are the main output neurons. Give output to other cortical areas and corticospinal tract. Mayor output
What are the two subareas from the thalamus that is good to remember?
The two are: (reference points)
Lateral geniculate nucleus –> that where the tracts from the eyes connect to the thalamus and project them back to the visual cortex.
Medial geniculate nucleus –> that’s where the auditory system comes in.
Explain a bit about a stimulus and how its being processed. (thalamus)
Stimulus –> thalamus –><– somatosensory cortex (primary) –> association cortex (unimodal or multimodal) [you may already learned things then –><– hippocampus]
Also
Stimulus –> thalamus –> <– somatosensory cortex (primary) –> <–motor cortex (primary) [could already give ana output]–> premoter cortex –><– basalglia
Nucleus accumbens gives motivation.
Explain a bit about the diffuse modulatory systems.
You have different activities in some brain areas. These activity needs to be regulated being modelated. That happens by the diffuse modulatory systems. You will find the neurotransmitter, but not the neuron that makes it.
explain dopamine.
- Nigrostriatal circuit: regulation of motor functions.
- Mesolimbic-cortical circuit: regulation emotional behavior
Explain serotonin.
- from raphe nuclei into the brain
- emotion regulation, mood(depression), self confidence, sleep, aggression
Explain noradrenalin
- from locus coeruleus into the brain.
- Arousal, mood, euphoric behavior, stress, fear.
Explain acetylcholine
- From fore-and hindbrain nuclei into multiple brain areas.
- Concentration, learning and behevior
Give some info about GABAergic interneurons.
Gabaergic interneurons.
- Is the main inhibitory neurotransmitter in the central nervous system.
- GABAaergic inhabitation is seen at all levels of the CNS, including the hypothalamus, hippocampus, cerebral cortex.
- GABAaergic inhabitation; abundant in the brain, with 50% of the inhibitory synapses in the brain being GABA mediated.
