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Unit 2 - Subcortical systems, neurochemistry and brain function

Subcortical anatomy: Most of the five major subdivisions of the brainare subcortical.

I. Telencephalon (cortical - part of forebrain)- also contains ____________ and ______________, which are

subcorticalII. Diencephalon (_________, ____________ - part of forebrain)III. Brainstem

- mesencephalon (_________)- metencephalon (_____, ___________ - part of hindbrain)- myelencephalon (________________ - part of hindbrain)

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I. Subcortical telencephalon: basal ganglia- corpus striatum (caudate nucleus and putamen)- globus pallidus (together with putamen - called ______________)- nucleus accumbens (ventral part of striatum)

- Caudate nucleus

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I. Subcortical telencephalon: basal ganglia (continued)- putamen

Putamen

LateralventricleCorpus

callosum

- Globus pallidus

Globuspallidus

Putamen

Caudate

Anteriorcommissure

Thalamus

Corpuscallosum

Basal ganglia generally involved in __________________________________________.

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I. Subcortical telencephalon: basal ganglia (continued)- nucleus accumbens (ventral striatum - involved in _____________)

1. ________

3. ________

2. _______________

5. __________________

4. _________________

Caudate

Putamen

Globuspallidus

Thalamus

Hypothalamus

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I. Subcortical telencephalon: limbic system- ______________- ___________- ______________________- ___________________- ___________________

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I. Subcortical telencephalon: limbic system (continued)- hippocampus and amygdala (with fornix)

Corpuscallosum

fornix Amygdala

Hippocampus

Anteriorcommissure

- cingulate gyrus

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I. Subcortical telencephalon: limbic system (continued)

Limbic structures generally involved in the regulation of motivatedbehaviors (feeding, fleeing, fighting, sexual behaviors) and learning/memory.

- amygdala associated with _____________________________- hippocampus associated with ___________________.- septal nuclei associated with __________.- fornix connects septal nuclei and hippocampal formation(fimbria-fornix)

- fornix also provides hippocampal output to hypothalamus (mammillary bodies).

Hippocampus

Amygdala

Cingulategyrus fornix

caudate

putamen

GP

Mammillarybody

cc

ic

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II. Diencephalon composed of __________ and ______________Thalamus: major relay station between sensory inputs to thebrain and neocortex (for most sensory systems)

- layer VI of neocortex provides significant feedback to thalamus

Cross-section through thalamus shows massa intermedia, amajor thalamic fiber decussation system across third ventricle.

Massa intermedia

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II. Diencephalon (continued)Hypothalamus: important in the control of ________________________________________________________________

- note the proximity of thepituitary gland, connected tothe hypothalamus via the_______________

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III. Brainstem:

Midbrain

Thalamus

- midbrain (mesencephalon) contains ________________________(below and above aqueduct, respectively)

-Colliculi: _______________________________

-PAG (__________)

-Reticular formation:___________ ______________

-Red nucleus: ___________________ ____________-Substantia nigra:________________________________

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III. Brainstem:Pons and cerebellum

- pons contain nuclei for several ________________- divided into a ventral portion (basis pontis) and a dorsalaspect (tegmentum)

- basis pontis a major relay of _________________________- tegmentum contains reticular formation, tracts, and cranial nuclei

Basis pontis

Tegmentum

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III. Brainstem:Medulla oblongata: contains several tracts, nuclei of reticularformation and several cranial nerves, much like pons.

- Example: Hypoglossal nerve (XIIth cranial nerve): origin of neurons innervating muscles of the tongue.

- Example: pyramids - begins in precentral gyrus, enters internalcapsule to join cerebral peduncle, forms pyramids, decussatesand enters spinal cord as corticospinal tract (lateral funiculus)

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Basic chemistry and biochemistry - building blocks of biology

Remember Star Trek? We are “carbon-based” creatures, ascompared to other extraterrestrial races (if any exist)!!!

The chemical elements (periodic table) in nature combine in variousways to form molecules (compounds).

- most common elements in biochemical compounds are:C -O -H -N -- other less common by very important ones are:S -P -Most of the cellular components in our body are made of carbon

containing molecules.

Atoms: smallest particle (unit) of an element that maintains theproperties of that element.What are atoms made of ?

Molecules are formed when 2 or more atoms combine.Examples:

When more than one compound are mixed together, these are calledmixtures; these are most often found in nature, including our body.Examples:

What are ions?

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Three (3) basic types of complex molecules that are important forcellular structure and function:lipids, proteins, and nucleic acids

Each of these complex molecules is made up of essentially a longchain of a simpler molecule.

1. Lipids: made up of ___________________________________.- stored in fat cells (adipose cells) which serve as ____________________.

- also very important in the formation of _________________.- normally made up of a charged ________________ and the __________________________.

- there are 3 different types of membrane lipids: phospholipids,glycolipids, and cholesterol.

What are phospholipids (phosphoglycerides)?

carbon chains glycerol phosphate

Lipids can interact in different ways depending on the mediumaround them:

- aqueous (polar) solvents (such as water)- non-aqueous (organic) solvents (such as chloroform)

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2. Proteins: made up of long chains of ___________ (called residues).- proteins play a role in nearly every biological function known(__________________________________________________________________________________________________________________________________________).

- 20 different amino acids serve as the building blocks ofproteins.

- each amino acid is made up of _____________, a _________________, and a ____________, which differentiates amino acids.

- amino acids can be combined in any order (variety of proteins).- short chains are called: ___________________________.- long chains are called: _________________.

Normally, phospholipids aggregate as shown in top center to formcell membranes (_______________).

In aqueous solvent In organic solvent

micelle bilayer inverted micelle

amino group

carboxyl group

side chain

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Examples of different amino acids; notice the different side chains

Proteins are said to have structures:- primary structure: ________________________________________- secondary structure: _________________________________________________________________________________________________________________________________________________

- tertiary structure: ________________________________________________________________________________________

- quaternary structure: _____________________________________

Also, proteins are said to have different domains (examples:extracellular domain, intracellular domain, transmembrane domain,binding domain).

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Many proteins are associated with the cell membrane:- integral proteins have peptide domains that insert _____________________________, once or several times.

Examples of secondary structures based on á-helix and â-sheet

á-helix â-sheet

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3. Nucleic acids (DNA, RNA): __________________________- the “blueprint” of life.- as with amino acids, nucleotides combine in any order.- only four different types of nucleotides (slightly different for DNAand RNA).

- single nucleotides made of three components:a. __________b. ____________________________________________c. __________________________________________________

__________________

Phosphates

Deoxyribose

Base

The 4 bases of DNA

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Protein synthesisWhere are proteins produced in our body?

How does a cell know how to make a particular protein?- It needs to begin with a code which tells the cell which amino acidsto string together to make a particular protein.

- That code is provided by a gene (blueprint of life).- It is believed that the genome contains approximately 60,000genes (Human Genome Project).

- Question: Do all cells in our body have the same genes (i.e. geneticcode)?

- Question: Are all stretches on DNA part of genes?

Major steps in protein synthesis:

DNA →→ mRNA →→ protein

1. ___________: make an mRNA copy of a specific gene (in nucleus)

2. mRNA transported to cytoplasm (outside of nucleus)

3. _________: use “code” from mRNA to build a protein (successivetriplets (3 nucleotides) code for one of 20 amino acids to be linked.

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Illustrated steps of protein synthesis

Puzzle: What makes a liver cell different from a neuron?

Protein synthesis is an ongoing dynamic process.