Cerebrum II

Question 1

Subcortical structures

Answer 1

-olfactory system
-hippocampus
-caudate nucleus
-basal ganglia
**limbic system: behaviour and emotions, survival/reproduction

Question 2

Olfactory system

Answer 2

-oldest part of brain, linked to learning and memory
-CN I goes directly to olfactory system (only CN that is direct, and does not go to thalamus)
-includes piriform lobe and amygdala and hippocampus

Question 3

piriform lobe

Answer 3

-important for learning and memory
-within the olfactory system
-gives rise to the amygdala and hippocampus

Question 4

Amygdala

Answer 4

-nucleus within piriform lobe or olfactory system
-perception and conscious awareness of fear
**damage here results in animals conducting more risky behaviour. Also targeted by Rabies virus.

Question 5

Hippocampus

Answer 5

-C-shaped structure curing rostral dorsally
-bilateral structure
-large nucleus in subcortical region
-forms memory and learn new behaviours

Question 6

Smells

Answer 6

-certain smells evoke emotional response
>form memories that are important for survival (storage location of these memories is unknown)

Question 7

Caudate nucleus

Answer 7

-part of basil ganglia which is important for initiating voluntary motor movements and control

Question 8

Lesion in cerebral cortex and subcortical structures

Answer 8

1.Behaviour
>loss of learned behaviours (house training, tricks, where things are in the house)
>increased activity (circling towards side of lesion, pacing)
>abnormal behaviours (head pressing common in large animals, inappropriate fear or aggression, inappropriate innocuous behaviours (chewing, fly biting – psychomotor seizures/complex partial seizures)
>tremors
2.Loss of vision= cortical blindness
3.Seizures

Question 9

Seizures

Answer 9

-an involuntary sudden electrochemical disturbance within the brain resulting in temporary changes to mentation/awareness, muscle tone and behaviours
**Neurons in the cerebral cortex become spontaneously activated, which spreads to nearby cortical areas through white matter tracts
>can connect L and R hemispheres via corpus callosum

Question 10

Types of seizures

Answer 10

-grand mal/full body
-partial/focal
-complex partial

Question 11

Generalized motor seizures (grand mal)

Answer 11

-most common seizure type
-loss of consciousness
-animal becomes recumbent (lateral recumbency) with rigid extended limbs (tonic-clonic) = paddling or running movements
-visceral component= hypersalivation, urination, defecation, dilated pupils (pre-ictal signs)
-usually short lasting

Question 12

Post-ictal period

Answer 12

-period when seizure ends
- regain consciousness, but will often be disoriented

Question 13

Neurological causes of seizures

Answer 13

-inflammation
-neoplasia
-swelling
-idiopathic seizures (epilepsy- pattern of repeated seizures with no known cause; no identifiable causes/no structural abnormalities)

Question 14

Non-neurological causes of seizures

Answer 14

**metabolic
-hypoxia
-hypoglycemia
-hyperthermia
-toxin ingestion (chocolate, xylitol)
-liver disease

Question 15

Partial motor seizures

Answer 15

-abnormal muscle tone in a localized region of the body, often involving the face
**large portion of the motor cortex is dedicated to the face
-animal is conscious, and they won’t have post-ictal phase

Question 16

Complex partial seizures

Answer 16

-also called psychomotor seizures (temporal lobe seizures)
◦ humans will sometimes hear noises
-abnormal activity within the behavioural regions of the brain
◦ aggression, biting behaviour, chasing tail
◦ coordinated abnormal movement/behaviour