case 7 Flashcards
MPTP
produces parkinsonism by destroying nigral cells, accidental exposure, neurotoxic cause crosses BBB destroys nigral cells. Manganese oxide can also cause PD
cognitive labelling theory
: Physiological arousal is necessary for
emotional experience but the nature of the arousal is
immaterial: its how we label it that matters
5 components of an emotional system
expression changes. physiological arousal. behaviour. subjective affect. cognitive appraisal.
james lange theory of emotions
Emotionally significant events lead to physiological changes and the
experience of emotion is a CONSEQUENCE of these bodily responses
cannon bard theory of emotions
Emotionally significant events INDEPENDENTLY cause emotional
experience and physiological responses.
fear
lesions in amygdala down abolish it.
striatum
caudate and putamen
Direct basal ganglia pathway
glutamate signals to striatum, inhibitory signal to GPi and SNpr. So no longer able to inhibit thalamus. thalamus sends ok message to cortex to allow movement. SNpc sends dopamine to D1 causing it to be more active.
indirect basal ganglia pathway
frontal lobes send excitatory signal to striatum, striatum inhibitory to GPe. GPe no longer inhibits STN. STN active excitatory signal to GPi. GPI more inhibitory so thalamus more inhibited so doesnt send message to motor cortex, dec movement. DA binds D2 inhibitory of this pathway so more excitation of movement.
acetylcholine
major efferent NT of PNS. AcoA and choline with choline acetyltransferase. Hydrolysed by acetylcholinesterase into acetate and choline. muscarinic receptors most in brain.
glutamate
excitatory neuron in CNS. elevated conc in neural injury is toxic to neurons. Doesnt cros BBB so synth in neurons from glucose or glutamine. Glutamine released glial cells, glutaminase turns it. back to glutamine via glutamine synthetase. Ionotropic (NMDA AMPA) allow passage of NA K Ca. when hyperpolarised Mg blocks pore. requires glycine.
GABA and glycine
inhibitory. GABA formed from glutamate by glutamic acid decarboxylase GAD. converted to succinate by GABA transaminase. GABAa and GABAc ionotropic. GABAb metabotropic. GABAb inhibit Ca channels activate K. glycine is abundant in the spinal cord grey matter of ventral horn.
substantia nigra
latin for black substance due high levels of neuromelanin. nigrostriatal pathway arises from SNoc and projects to caudate and putamen. primary input to basal ganglia. dysfunctions or degeneration of cells cause parkinsons.
ventral tegmental area
mesolimbic pathway - VTA to limbic structures, reward. Mesocortical-VTA to PFC. working memory and attention.
input into basal ganglia
corticostriatal pathways largest source, through internal capsule to striatum. visual and auditory dont go here. topographically mapped. medium spiny neurons. spines allow to integrate inputs from variety of cortical thalamic and brainstem structures. axons synapse on GP and SNpr. Sensory and motor go to putamen, PFC caudate.
output from the basal ganglia
medium spiny neurons go to GP and SNpr. GABA then to GPi SNpr. direct. or indirect pathway.
interneurons
can be inhibitory or ecitatory.
D1 D2
D1 inc dynorphin which stimulates direct pathway. D2 dec enkephalin which inhibits indirect pathway.
ansa lenticularis
course from GPi to thalamus, looping course ventrally under internal capsule.
lenticular fasciculus
straight through internal capsule pass STN before turning to enter thalamus. join with ansa lenticularis to form thalamic fasciculus.
lobes of cerebellum
anterior posterior and flocculonodular (functions with vestibular system) each fold is called a folium.
cerebrocerebellum
regulates highly skilled movements. eye movements. speech, hand eye coordination. projects to dentate nucleus.
vestibulocerebellum
comprises flocculus and nodulus. posture and equilibrium. projects to lateral vestibular nucleus.
spinocerebellum
medial part. input directly from SC. movements distal proximal and eye movements. projects to fastigial and interposed nuclei.
superior cerebellar peduncle
output from cerebellum. post lobe to midbrain.
middle and inf cerebellar peduncle
inputs. from medulla to ant lobe sensory info about posit of body. middle from pontine nuclei desired position of body. from ipsilateral side of body.
dentate nucleus
all outputs originate from the deep nuclei so a lesion to the nuclei is like a lesion to the entire cerebellum. a lesion will effect the ipsilateral side of the body unlike the cortex. recieves input from the lateral cerebellar hemispheres and from cerebellar afferents from the corteex, projects to the red nucleus and VL thalamic nucleus.