Neuro

MidBrain

(Mesencephalon): Small structure connecting hindbrain and forebrain

• Interconnects with some cranial nerves 

• Red nucleus: coordinates muscles signals 

• Reticular formation: works with medulla, regulates sleep, temperature, arousal

Tectum (Major Structures along it)

• Superior colliculi: integrates visual information, coordinates eye movement with attention

• Inferior colliculi: Integrates auditory information, coordinates head movement with attention

Forebrain

(prosencephalon): ?

Diencephalon

• Thalamus : Major relay center

• Hypothalamus : Interface with endocrine system

Telencephalon

• Limbic System: Emotion, memory formation 

  • Amygdala 

  • Mammillary bodies - connected to the hypothalamus, processing emotions related to hormones in the body 

  • Hippocampus 

  • Fornix 

  • Septal nuclei - pleasures/reward systems 

  • Cingulate gyrus - coordinate activity

  • Olfactory bulb - process smell 

  • Stria terminalis - Two lines that run along thalamus and connect to amygdala, simply discomfort of uncertainty 

Basal Ganglia

• Reciprocates activity with cortex

  • Caudate nucleus 

  • Putamen

  • Globus Pallidus 

  • Substantia nigra (midbrain)

Cerebral Cortex

• Long-term memories, perception ( (Make note of basal ganglia and limbic system and know where they are located within the brain, check textbook)

• Know different lobes: occipital, temporal, parietal, frontal 

  • Occipital lobe processes vision 

  • Temporal - 

  • Parietal lobe

  • Frontal lobe- planning, forward thinking things 

Sulci

• folds in, fissure

  • Sylvian fissure: Dividing line of frontal, parietal and temporal lobes 

  • Central sulcus: Dividing line of frontal and parietal lobes

Gyri

• folds out, raised portions

  • Postcentral gyrus: location of somatosensory cortex

  • Precentral gyrus: location of motor cortex

    
    

Support system (Two)

• Meninges 

  • Dura mater: tough outer shell 

    Pia mater: softer inner shell 

    Subarachnoid space: between dura and pia mater, filled with csf. Made of arachnoid “web-like” matter 

• Ventricular system: Fluid-filled cavities in brain

  • Lateral ventricle

    • Choroid plexus: produces CSF

      Third ventricle 

      4th ventricle 
      

Cerebral spinal fluid (CSF)

• Filtered blood, helps clear nervous system of debris. Mild shock absorber 

Vascular System (Two main arteries)

• Anterior and middle cerebral arteries

  • supply blood to front ⅔ of brain. Supplied by carotid arteries 

• Posterior cerebral arteries

  • supply blood to rear ⅓ of brain. Supplied by vertebral arteries, then basal artery. 

• All converge at Circle of Willis 

  Works with glymphatic system 

  
  

Neuroimaging: Structure

• Computerized axial tomography (CAT) 

• Magnetic resonance imaging (MRI) 

• Diffusion tensor imaging (DTI)

  • Fractional anisotrophy (FA)

  • DTI tractography

Neuroimaging: Activity

• Positron Emission Tomography (PET) 

• Functional magnetic resonance imaging (fMRI)

• Optical imaging 

• Transcranial magnetic stimulation (TMS) 

• Magnetoencephalography (MEG)

• Electroencephalography (EEG)

(Training needed in interpretation of neuroimaging 

Can easily get the wrong idea)

Neurophysiology: Neuronal Biophysics 

• Resting potential 

  • Nernst Equation 

• Action Potential
  

Neurophysiology: Neurotransmission

• Presynaptic membrane

  • Exocytosis 

• Receptors 

• Circuits

Neurophysiology: Information Processing

• Summation

Neuronal Biophysics: Resting membrane potential

• Resting potential: the difference in electrical charge between the inside voltage and the outside voltage 

  • Not receiving signals 

  • Not sending signals 

• Typically, -65mV

  • - -50 to -80mV

    - “Polarized” 

Neuronal Biophysics: Ions within “cellular” fluids

• Ions within intracellular and extracellular fluids

  • Potassium 

  • Sodium 

  • Calcium 

  • Chloride 

Equilibrium potential

•  the difference in charge between inside and outside of the neuron after balancing several other factors

Electrostatic pressure 

• The anti attraction of like charged particles 

• The attraction of oppositely-charged particles 

Diffusion

• Entropic movement of particles from high densities to low densities 

• Concentration gradient: density as a function of location 

Concentration gradient

• density as a function of location 

Selectively permeable membrane

• boundary of neuron allows passage of some ions and not others 

Ion channels

• specialized proteins, pores in the membrane 

• Sodium-Potassium pumps: energetically-expensive active enzymes 

• Exchange 3 intracellular na+ for 2 extracellular k+ 

• Net negative intracellular space
  

Nernst Equation Theory

• Can predict the equilibrium potential for a permeable membrane given a specific ion 

  • Expressed in terms of extracellular voltage, but can easily refer to the inside voltage 

  • An approximate predictor. Assumes only one ion influences potential and the membrane is perfectly permeable.

Goldman Equation 

• Goldman-Hodgkin-Katz voltage (GHK) equation 

• An update to Nernst Equation which accounts for multiple ions and multiple levels of permeability 
  

Nernst Equation

Ex = (58/Ax)MV * log10(Cout x/Cin x)

• X: A specified ion 

• Ax : The ion valence

• Cout x : The ion concentration on the outside o fthe neuron 

• Cin x: The ions concentration on the inside of the neuron 

• 58: An approximated constant 

• Goldman equation would tell the charge of the whole neuron 
  

Action Potential 

Action Potential: Brief, but intense change in polarization which regenerates in nearby membrane 

• Essential for neural communication 

• Occurs when cell membrane is depolarized to threshold level

• Depolarization: Reducing the potential voltage difference towards zero 

• Hyperpolarization: Increasing the potential away from zero 

• Ion concentrations are frequently in flux, perturbed 

  • opening/closing of ion channels 

    
    
    

Red nucleus

• coordinates muscles signals 

Reticular formation

• works with medulla, regulates sleep, temperature, arousal

Superior colliculi

• integrates visual information, coordinates eye movement with attention

Inferior colliculi

• Integrates auditory information, coordinates head movement with attention 

Thalamus

Major relay center in the Diencephalon

Hypothalamus

Interface with endocrine system in the Diencephalon

Limbic System

• Emotion, memory formation

Mammillary bodies

•  connected to the hypothalamus, processing emotions related to hormones in the body

Septal nuclei

• pleasures/reward systems

Cingulate gyrus

• coordinate activity

Olfactory bulb

• Process smell

Stria terminalis

• Two lines that run along thalamus and connect to amygdala, simply discomfort of uncertainty

Occipital lobe

•  processes vision

Frontal lobe

• planning, forward thinking things

Sylvian fissure

• Dividing line of frontal, parietal and temporal lobes

Central sulcus

• Dividing line of frontal and parietal lobes 
  

Gyri

• folds out, raised portions

Postcentral gyrus

• location of somatosensory cortex

Precentral gyrus

• location of motor cortex

Dura mater

• tough outer shell

Pia mater

• softer inner shell

Subarachnoid space

• between dura and pia mater, filled with csf. Made of arachnoid “web-like” matter 
  

Ventricular system

• Fluid-filled cavities in brain

Choroid plexus

• produces CSF
  

What is 1

Thalamus: Relays sensory/motor signals from various locations to cerebral cortex. It helps with alertness, sleep, consciousness, learning and memory.

What is 2

Caudate nucleus: Processes visual info, control movement, working memory, cognitive function and emotions.

What is 3

Putamen: The putamen is involved in learning and motor control, including speech articulation, language functions, reward, cognitive functioning, and addiction

What is 4

Globus Pallidus: helps with movement, cognitive/emotional functions. Inhibits undesired movements

What is 5

Amygdala: helps assess/respond to threats and challenges by evaluating emotional importance of sensory info.

What is 6

Subthalamic nucleus: performs action selection, implement “hyperdirect pathway” of motor control.

What is 7

Substantia nigra:

Reticulata: helps with eye movements with eyes, ability to learn/think

Compacta: helps with learning, judging risks/reward, motivations

What is 8

Septal nuclei: involved with experience of pleasure

What is 9

Mammillary body: helps with recollective memory

What is 10

Amygdala: Controls fear, processes what you hear and see. Interacts with aggression, learning thru rewards/punishments

What is 11

Hippocampus: Organization/storage of new memories. Transfer center for long term memory. Helps with Spatial memory and navigation.

What is 12

Stria terminalis: Relays olfactory info thought to be related to reproductive behavior to the medial preoptic area and anterior nucleus of hypothalamus

What is 13

Thalamus: Relays sensory info, relaying motor info, priortizing attention. Plays role in attention span, consciousness, memory/thinking

What is 14

Cingulate gyrus: coordinates sensory input with emotions, emotional responses to pain, regulates aggressive behavior, maternal bonding, language expression

What is 15

Fornix: Deals with cognition, memory and emotions

What is 16

Olfactory bulb: Acts as the main relay structure of the olfactory pathway