Altklausur

Anabolic hormones released with high level of leptin: ACTH and TSH

• Leptin = hormone primarily produced by fat cells, signal from the fat cells to the brain that the fat cells are full

• Nucleus arcuatus = “brain sensor” that responds to varying levels of leptin in the  blood stream

Rewards in the future are less likely to materialize and lose subjective value the more distant in future.

1. Phineas Gage, Scientist: John M. Harlow; Severe lesions in left frontal lobe. He got damage of higher order cognitive functioning. 

2. Henry Molaison, Scientist: William Scoville; Lobectomy, removed hippocampus. Scoville and Milner discovered impaired explicit memory formation. Left with Anterograde amnesia and mild retrograde amnesia.

3. Louis Victor Leborgne (Monsieur Tan): Scientist: Pierre Paul Broca - Damage on inferior frontal gyrus, left hemisphere, areas: BR44/45 damaged.-> intact language perception + tonation, no language production ("thinks he forms words") - Then called aphemia, later aphasia.

Lateral PFC

1. Alpha waves → during resting, relaxation 

2. Beta waves → alertness, attention 

3. Gamma → problem solving, learning 

4. Delta → deep dreamless sleep

• Apnea test to check for spontaneous breathing

• Absence of brain-stem reflexes (such as cough reflex, light reflex)

• Present neurotransmitter (VL on food slide 7):

• Acetylcholine always present in pre ganglionic neurons for both para and symp

  • Final transmitter onto the organs in the sympathetic branch = Epinephrine and Norepinephrine

  • Final transmitter onto the organs in the parasympathetic branch = Acetylcholine

• Two neurons: pre and post ganglionic neurons 

Exception: the adrenal medula does not have a post ganglionic neuron, because it releases the neurotransmitters (epinephrine and norepinephrine) into the blood by itself

6 Layers (Molecular layer, External granular layer, external pyramidal layer, internal granular layer, internal pyramidal layer and multiform layer).

Thalamus acts as gatekeeper. Input at layer 4, information is sent to layers 2|3 then to layer 5 and finally,  either to the cortex. Basal ganglia or to layer 6.

• Medio-lateral: intero- (medial PFC) and exteroceptive (lateral PFC)

• Ventro-dorsal: Conceptualization of what (ventral) and where (dorsal)

• rostro-caudal :  Abstractness of Concepts (at rostrum more abstract, towards central sulcus more and more concrete)

• Frontal lobe (Conscious movement, emotional expression)

• Parietal lobe (Spatial orientation, cognition)

• Occipital lobe (Colour recognition, reading)

• Temporal lobe (Memory, speech)

Basal ganglia

• Persistent activity → 

  • individual prefrontal neurons fire persistently for their specific memorized item 

• Transient activity → 

  • Working memory is associated with bursts of oscillatory neural activity → this allows the brain to process distractions at the same time without losing focus on the main task 

• Silent activity → 

  • Task-relevant input is stored in the network by altered synaptic weights → memory storage not by activity but by connection strength

• Working memory networks

  • Rhythmic changes in excitability could enable selective read-out of information

  • the information is encoded phase-dependent

Their antagonism to dopamine receptors, specifically D2-receptors.

Main side effect: EPS, autonomic, hyperprolactinaemia 

Advantage of atypical antipsychotics:  Improved effectiveness against negative symptoms.  Regarding side effects they alleviate the extrapyramidal symptoms

Yes, they have a medial PFC, but they don’t have a lateral PFC.

wrong question: instead of asking if they have the same brain area or structure, one should ask how they solve complex tasks → finding functional analogue structures in animal brains

• Polar opposites

  • AN patients heavily limit their food intake, due to disturbed self image 

  • BE is an eating disorder with frequent and recurrent phases of high food intake. Patient loses control over their eating habits → executive dysfunction 

• Neurotransmitter systems disrupted in AN:

  • Dopamine (DA) and Serotonin (5- HT) metabolism. Research indicates in AN patient, 5-HT is increased and DA is decreased.

• Involved in spatial recognition

• Grid cells 

  • located in the entorhinal cortex (as well as border cells)

  • Input to place cells 

• Place cells located in dorsal hippocampus

Desensitization towards reward associated with the food (Decreased availability of D2R receptors)

Probably meant as a signal to stop searching for food, but in permanent availability of yummy food, instead may cause increased consumption to compensate for decreased reward.

=> Binge Eating

- H.oeconomicus makes rational decisions to maximise value for himself, unaffected by emotions. He has absolute preferences, never changing regardless of the comparison. 

- H. Sapiens has relative preference, which shift depending on the objects being compared. He’s confused by uncertainty and risk.

The capacity of take other individual’s perspective to “read minds”.

Observe food staching of Corvids. When the bird knew it was observed by another bird it relocated the cache.

Experiments on some primates, dogs, pigs, goats and some birds

• Homo sapiens can be manipulated into picking a specific option depending on the way the options are presented → framing effect

• involves the amygdala (nucleous involved in fear) -> 

  • when framed for gain -> amygdala was more active for risky options. 

  • when framed for loss -> amygdala more active for sure options

provides a practical method for assessment of impairment of conscious level in response to defined stimuli:

• Eye opening

• Motor response

• Verbal response

The enteric nervous system is part of the vegetative nervous system and often called the „little brain“ of the gut. It is embedded in the inner walls of the esophagus, the stomach, the gut, pancreas and gall bladder. 

Called a „brain“, as it has a more or less autonomous functions that include sensory neurons (stretch, tension, chemoreception) connecting to motor neurons, that control gut movements but also the production of enzymes etc.

• Excitatory postsynaptic potential

  • Synaptic potential that makes the postsynaptic neuron more likely to generate an action potential

  • Temporary depolarization of postsynaptic membrane potential (caused by the flow of positively charged ions (Na+) into the postsynaptic cell)

→ increase the likelihood that the postsynaptic cell reaches the threshold for firing an action potential

• Inhibitory postsynaptic potential

  • Synaptic potential that makes the postsynaptic neuron less likely to generate an action potential

  • inhibitory presynaptic neurons release neurotransmitters that bind to postsynaptic receptors (changes the postsynaptic membrane permeability for certain ions)

 A more negative postsynaptic potential is generated (hyperpolarization)

Neurons respond:

-vertical: same orientation, ocular dominance

-horizontal: different orientation, left ocular dominance

Frequency, amplitude, phase

• Alcohol: GABA

• Nicotine: ACH

• Heroine: DA

Norepinephrin (NE): attention, arousal, stress 

Dopamine (DA): motivation, curiosity, reward expectation

Serotonin (5-HT): sedation, mood and social behavior, appetite and digestion, sleep, memory and sexual desire and function

Acetylcholine (Ach): focused attention, promoting learning

Glutamate / GABA: excitatory / inhibitory (ubiquitary)

One of the essential glutamate receptors of long time potentiation (also important: AMPA and GABA)

a)  

• Brain gets less sensitive towards the reward associated with food (increase in reward threshold)

• Deficits in brain reward circuitry (more and more food is necessary to reach the same level of reward)

b)

• Appearance of food can greatly influence the hedonic value (“das Auge isst mit”)

• In times of stress food rich in carbs increases the “mood-rising effect” caused by higher serotonin levels (F531)

• Useful because it helps the animal adapt to changing environments and ensures food intake (energy necessary for survival), the animal seeks the most pleasurable food with the highest nutritional benefits

• Cerebellum decreases the hedonic value of food à “brake” on neural networks that promote food intake (assures right amount of food intake)

a) Midbrain (mesencephalon), pons, medulla oblongata 

b)

• the substantia nigra plays an important role in Parkinson’s (dopamine producing cells in the substantia nigra start to degenerate)

• the substantia nigra is part of the tegmentum

Delta and alpha waves

e.g. Phineas Gage: damage of prefrontal cortex (iron rod through skull)

1. damage higher order cognitive functioning

1. Failure to plan

1. Disturbance of social behavior

1. Disturbance of working memory

2. Disturbance of language/speech production

3. Disinhibition

• classification by time course: working memory à storage and manipulation of memories, active exploitation of long-term memory

• (contrast short-term memory: only temporary storage of information, passive sensory trace)

• temporary activation of updated long-term memory network for organization of near actions

Working memory is associative; it provides meaning and purpose, it has historical and behavioral context

storage and manipulation; active exploitation of long-term memory

• brain death and coma: absence of arousal, consciousness and awareness

• Vegetative state: no awareness, but fully awake and arousable

• Minimally conscious state: fully arousable, limited awareness (yes/no responses possible, follow simple commands)

• Locked in syndrome: fully aware and arousable

a) Hippocampus (experiments conducted on anesthetized rabbits )

b) GABA, NMDA, AMPA

• Eye opening

• Motor response

• Verbal response

• L4 is thicker in the sensory cortex

• Layer IV has its focus on the input / incoming information

• the sensory cortex receives lots of input and has a thick layer IV, the motor cortex focuses on output and therefore has a very small layer IV but large layer V

Chemical substances that change brain function and result in alteration in perception mood, consciousness, behaviour

1.

• “little brain” of the gut: more or less autonomous functions (including sensory neuron connected to motor neurons, that control gut movements and production of enzymes)

• Number of neurons in the enteric system are about the same as in the spinal cord 

2.

• Embedded in the inner walls of the esophagus, stomach, gut, pancreas, gallbladder 

3.

• Via sympathetic and parasympathetic fibers

The mesolimbic and mesocortical pathways originating from the VTA target brain regions such as the nucleus accumbens and PFC -->

dysfunction in these pathways are implicated in psychotic disorders, e.g., schizophrenia

• Weight gain

• extrapyramidal symptoms

• hyperprolactinemia

Layer 4 is present there, most of the lateral prefrontal cortex in humans is granular. That is a big difference between primates and other species. It is the most specialised and sophisticated part from an evolutional point of view.