9. Neurons release neurotransmitters to communicate
• Receive information by
capturing neurotransmitters
released in the synaptic cleft
1) Dendrites:
• Integrates information from the
dendrites. Contains the nucleus
and controls hereditary
characteristics
2) The cell body or soma:
• tube-like structure that
transmits information
3) Axon:
10.
11. Fatty
substance acts
as an insulator
Speeds up
conduction
Glial cells
Hold neurons
together
Provide
neuron with
nutrients
Remove
cellular debris
14. Negative resting
state
Potassium and
Sodium ions switch
places which
releases
neurotransmitters at
the synaptic cleft
All or none
principle: If
sufficiently
stimulated, will fire
to its full extent
19. All behavior results
from activity in the
cells of the nervous
system
Two divisions:
Central nervous
system
Peripheral nervous
system
20. Spinal cord and
brain
Sensory
neurons carry
info to CNS
Motor neurons
carry info away
from CNS to
muscles and
glands
21.
22. The Somatic Nervous
System
Sends and receives
sensory messages that
control voluntary motor
movement of the
skeletal muscles
Autonomic Nervous
System
Smooth muscles
Digestion
Heart rate
Breathing
23. Sympathetic
Arousal and expenditure
of energy
External threat
Fight or flight
Parasympathetic
Conservation of energy
Rest/relaxation
Meditation, hypnosis,
biofeedback
Can work together, not
just in opposition!
25. Control center for all
voluntary and most
involuntary behavior
Brain Areas:
Cerebrum
Cerebellum
Brain Stem
Brain Divisions:
Forebrain
Midbrain
Hindbrain
27. Second largest structure
Coordinates habitual muscle
movements
Tracking target with eyes
Playing saxophone
Excitatory inputs for
maintaining smooth
movement and coordinating
motor activity
Ataxia: lack of coordination
28. Pons:
• Sleep
• Respiration
• Movement
• Cardiovascular activity
• Facial expressions
Medulla
• Blood pressure
• Heart rate
• Breathing
Damage to medulla & Pons
• Failure can lead to death and loss of
bodily functions
29. Smallest region of the
brain
Relay station for auditory
and visual information.
The Functions:
• Visual and auditory systems
• eye movement.
30. Awareness, attention and sleep
Damage: disrupt sleep, permanentn coma-like sleep
Spinal cord
Hypothalamus
Forebrain
Reticular activating system projects
to thalamus and wakes you up
32. Our primitive
brain: system of
various structures
in forebrain
• Emotions
• Basic drives
• Learning
• Influence autonomic
nervous system and
endocrine system
33. Relays information
from the sensory
receptors to proper
areas of the brain
Wernicke-Korsakoff
Syndrome
• Thiamine deficiency
Korsakoff’s Syndrome
• Severe amnesia & Other
symptoms
43. Left controls right, right controls left side of body
Important distinctions of respective functions
Right is
for
Intuition,
Artistic,
Emotions
Left is for
Language
and Logic
44. Bundle of nerve fibers that bridge left and right hemispheres
Split-brain patients
52. EEG: Detects brain
waves; sleep research
CAT Scan: View brain
structure, 3-D picture,
sophisticated X-Ray
PET scan: Measures
chemicals (aka) glucose;
functional capacity of
brain
MRI: radio waves to see
structures
fMRI: Cobmines MRI
and PET scan; details of
structure and activity
How experts think, the power of framing, the miracle of attention, the weird world of cognitive biases and more…
Fifty years ago there was a revolution in psychology which changed the way we think about the mind.
The ‘cognitive revolution’ inspired psychologists to start thinking of the mind as a kind of organic computer, rather than as an impenetrable black box which would never be understood.
This metaphor has motivated psychologists to investigate the software central to our everyday functioning, opening the way to insights into how we think, reason, learn, remember and produce language.
Phineas P. Gage (1823 – May 21, 1860) was an American railroad construction foreman remembered for his improbable[B1]:19 survival of an accident in which a large iron rod was driven completely through his head, destroying much of his brain's left frontal lobe, and for that injury's reported effects on his personality and behavior over the remaining twelve years of his life—effects so profound (for a time at least) that friends saw him as "no longer Gage".
Long known as "the American Crowbar Case"—once termed "the case which more than all others is calculated to excite our wonder, impair the value of prognosis, and even to subvert our physiological doctrines"[2]—Phineas Gage influenced nineteenth-century discussion about the mind and brain, particularly debate on cerebral localization,[M]:ch7-9[B] and was perhaps the first case to suggest that damage to specific parts of the brain might induce specific personality changes.[M]:1[M3]:C
Gage is a fixture in the curricula of neurology, psychology, and related disciplines (see Neuroscience),[3][M7]:149 "a living part of the medical folklore"[R]:637 frequently mentioned in books and scientific papers;[M]:ch14 he even has a minor place in popular culture.[4] Despite this celebrity, the body of established fact about Gage and what he was like (before or after his injury) is small,[c] which has allowed "the fitting of almost any theory [desired] to the small number of facts we have"[M]:290—Gage acting as a "Rorschach inkblot"[5] in which proponents of various conflicting theories of the brain were able to find support for their views. Historically, published accounts (including scientific ones) have almost always severely distorted and exaggerated Gage's behavioral changes, frequently contradicting the known facts.
A report of Gage's physical and mental condition shortly before his death implies that his most serious mental changes were temporary, so that in later life, he was far more functional, and socially far better adapted, than in the years immediately following his accident. A social recovery hypothesis suggests that his employment as a stagecoach driver in Chile provided daily structure allowing him to regain lost social and personal skills.
https://www.youtube.com/watch?v=MvpIRN9D4D4
Anencephaly is the absence of a major portion of the brain, skull, and scalp that occurs during embryonic development.[1] It is a cephalic disorder that results from a neural tube defect that occurs when the rostral (head) end of the neural tube fails to close, usually between the 23rd and 26th day following conception.[2] Strictly speaking, the Greek term translates as "no in-head" (that is, totally lacking the inside part of the head, i.e., the brain), but it is accepted that children born with this disorder usually only lack a telencephalon,[3] the largest part of the brain consisting mainly of the cerebral hemispheres, including the neocortex, which is responsible for cognition. The remaining structure is usually covered only by a thin layer of membrane— skin, bone, meninges, etc. are all lacking.[4] With very few exceptions,[5][6] infants with this disorder do not survive longer than a few hours or possibly days after their birth.
A neuron (/ˈnjʊərɒn/ nyewr-on or /ˈnʊərɒn/ newr-on; also known as a neurone or nerve cell) is an electrically excitable cell that processes and transmits information through electrical and chemical signals. These signals between neurons occur via synapses, specialized connections with other cells. Neurons can connect to each other to form neural networks. Neurons are the core components of the brain and spinal cord of the central nervous system (CNS), and of the ganglia of the peripheral nervous system (PNS). Specialized types of neurons include: sensory neurons which respond to touch, sound, light and all other stimuli affecting the cells of the sensory organs that then send signals to the spinal cord and brain, motor neurons that receive signals from the brain and spinal cord to cause muscle contractions and affect glandular outputs, and interneurons which connect neurons to other neurons within the same region of the brain, or spinal cord in neural networks.
A typical neuron consists of a cell body (soma), dendrites, and an axon. The term neurite is used to describe either a dendrite or an axon, particularly in its undifferentiated stage. Dendrites are thin structures that arise from the cell body, often extending for hundreds of micrometres and branching multiple times, giving rise to a complex "dendritic tree". An axon is a special cellular extension that arises from the cell body at a site called the axon hillock and travels for a distance, as far as 1 meter in humans or even more in other species. The cell body of a neuron frequently gives rise to multiple dendrites, but never to more than one axon, although the axon may branch hundreds of times before it terminates. At the majority of synapses, signals are sent from the axon of one neuron to a dendrite of another. There are, however, many exceptions to these rules: neurons that lack dendrites, neurons that have no axon, synapses that connect an axon to another axon or a dendrite to another dendrite, etc.
All neurons are electrically excitable, maintaining voltage gradients across their membranes by means of metabolically driven ion pumps, which combine with ion channels embedded in the membrane to generate intracellular-versus-extracellular concentration differences of ions such as sodium, potassium, chloride, and calcium. Changes in the cross-membrane voltage can alter the function of voltage-dependent ion channels. If the voltage changes by a large enough amount, an all-or-none electrochemical pulse called an action potential is generated, which travels rapidly along the cell's axon, and activates synaptic connections with other cells when it arrives.
Neurons do not undergo cell division. In most cases, neurons are generated by special types of stem cells. A type of glial cell, called astrocytes (named for being somewhat star-shaped), have also been observed to turn into neurons by virtue of the stem cell characteristic pluripotency. In humans, neurogenesis largely ceases during adulthood; but in two brain areas, the hippocampus and olfactory bulb, there is strong evidence for generation of substantial numbers of new neurons.[1][2]
Specialized types of neurons include: sensory neurons which respond to touch, sound, light and all other stimuli affecting the cells of the sensory organs that then send signals to the spinal cord and brain, motor neurons that receive signals from the brain and spinal cord to cause muscle contractions and affect glandular outputs, and interneurons which connect neurons to other neurons within the same region of the brain, or spinal cord in neural networks.
The insulating envelope of myelin that surrounds the core of a nerve fiber or axon and that facilitates the transmission of nerve impulses, formed from the cell membrane of the Schwann cell in the peripheral nervous system and from oligodendroglia cells. Also called medullary sheath.
A fatty, axon-enwrapping sheath that serves to speed up neural conduction, formed by concentric layers of Schwann's cell (peripheral) or oligodendrocyte (CNS) membranes; loss or damage leads to severe loss of neural function, as in multiple sclerosis.
Definition from: CRISP Thesaurus via Unified Medical Language SystemThis link leads to a site outside Genetics Home Reference. at the National Library of Medicine
The lipid-rich sheath surrounding axons in both the central and peripheral nervous systems. The myelin sheath is an electrical insulator and allows faster and more energetically efficient conduction of impulses. The sheath is formed by the cell membranes of glial cells (Schwann cells in the peripheral and oligodendroglia in the central nervous system). Deterioration of the sheath in demyelinating diseases is a serious clinical problem.
We are going to talk about the action potential and such, neurons are about communication. Here’s how.
Neuron functioning
In physiology, an action potential is a short-lasting event in which the electrical membrane potential of a cell rapidly rises and falls, following a consistent trajectory.
The resting potential tells about what happens when a neuron is at rest. An action potential occurs when a neuron sends information down an axon, away from the cell body. Neuroscientists use other words, such as a "spike" or an "impulse" for the action potential. The action potential is an explosion of electrical activity that is created by a depolarizing current. This means that some event (a stimulus) causes the resting potential to move toward 0 mV. When the depolarization reaches about -55 mV a neuron will fire an action potential. This is the threshold. If the neuron does not reach this critical threshold level, then no action potential will fire. Also, when the threshold level is reached, an action potential of a fixed sized will always fire...for any given neuron, the size of the action potential is always the same. There are no big or small action potentials in one nerve cell - all action potentials are the same size. Therefore, the neuron either does not reach the threshold or a full action potential is fired - this is the "ALL OR NONE" principle.
When a neuron is not sending a signal, it is "at rest." When a neuron is at rest, the inside of the neuron is negative relative to the outside. Although the concentrations of the different ions attempt to balance out on both sides of the membrane, they cannot because the cell membrane allows only some ions to pass through channels (ion channels). At rest, potassium ions (K+) can cross through the membrane easily. Also at rest, chloride ions (Cl-)and sodium ions (Na+) have a more difficult time crossing. The negatively charged protein molecules (A-) inside the neuron cannot cross the membrane. In addition to these selective ion channels, there is a pump that uses energy to move three sodium ions out of the neuron for every two potassium ions it puts in. Finally, when all these forces balance out, and the difference in the voltage between the inside and outside of the neuron is measured, you have the resting potential. The resting membrane potential of a neuron is about -70 mV (mV=millivolt) - this means that the inside of the neuron is 70 mV less than the outside. At rest, there are relatively more sodium ions outside the neuron and more potassium ions inside that neuron.
Make love not war chimpanzee. Could it be that Kanzi’s neural wiring contributes to his attentiveness and ability to use symbols and understand language? Is his ability to empathize with others what makes him a good listener and communicator?
It seems to be one of many factors, but certainly not the only prerequisite. As the structure/function debate continues, I still find it fascinating to see our notions of the brain as an impenetrable “black box” turn grayer with time.
Sensory signals come from up the spinal cord and are sent to appropriate areas in rest of forebrain
The Quick Facts
Location: Part of the forebrain, below the corpus callosum
Function: Responsible for relaying information from the sensory receptors to proper areas of the brain where it can be processed
The thalamus is similar to a doctor that diagnoses, or identifies, a patient's disease or sickness. It diagnoses different sensory information that is being transmitted to the brain including auditory (relating to hearing or sound), visual, tactile (relating to touch), and gustatory (relating to taste) signals. After that, it directs the sensory information to the different parts and lobes of the cortex. If this part of the brain is damaged, all sensory information would not be processed and sensory confusion would result.
Thiamine deficiency
Atrophy of neurons
Result of chronic alcoholism
Begins with Wernicke’s encephalopathy: mental confusion, abnormal eye movements, ataxia
Severe anterograde, retrograde amnesia
Confabulation
Regulation and coordination of movement
The Basal Ganglia are inhibitory, and put brakes on movement
Removal or Destruction of Amygdala
Placidity
Apathy
Hyperphagia
Hypersexuality
Agnosias
Removal or Destruction of Amygdala
Placidity
Apathy
Hyperphagia
Hypersexuality
Agnosias
Brain Lateralization
Contralateral representation
Left controls right, right controls left
Except olfactory
Brain lateralization
95-99% of right handed people are left brained
50-60% of left handed are left brained
Hempisphereic specialization
Left dominance:
Reading
Writing
Speaking
Spelling
Naming
Motor Control
Right Dominance:
Dominance:
Perceptual
Artistic
Musical
Intuitive
Body Image
Comprehension of visual, facial, verbal emotion
Problems:
Hemi-neglect, prosopagnosia, visual-perceptual disturbances, musical agnosia
Affective: Indifference, euphoria, hysteria, impulsivity, abnormal sexual behavior, etc…
3 main areas
Prefrontal cortex
Personality
Planning
Inhibition
Premotor area
Planning movement
Motor area
Instigate voluntary movement
Damage:
Loss movement
Personality, attention, thinking problems
Inability to express language (Broca’s aphasia)
Primary motor cortex
Precise control
Supplementary motor area
Planning and controlling movement
Premotor cortex
Primary motor control
Broca’s: left frontal lobe
Right Parietal Lesions -> Contralateral neglect
Left Parietal Lesions -> Ideational apraxia, ideomotor apraxia, Gerstmann’s syndrome
Apraxia: Muscles work, but you can’t coordinate movement
Anosognosia: Can’t recognize shit
Sensory cortex: top receives sensations from bottom of body and progresses down
Wernicke’s
Comprehend Speech
Left Hempisphere
Lesions:
Auditory agnosia
Halluciantions
Disturbances in auditorysensation and perception
Mediates:
Encoding, retrieval and storage of long-term declarative memories
Electrical stimulation can elicit vivid memories that were forgotten
Location: Bottom middle part of cortex, right behind the temples
Function: Responsible for processing auditory information from the ears (hearing)
The Temporal Lobe mainly revolves around hearing and selective listening. It receives sensory information such as sounds and speech from the ears. It is also key to being able to comprehend, or understand meaningful speech. In fact, we would not be able to understand someone talking to us, if it wasn't for the temporal lobe. This lobe is special because it makes sense of the all the different sounds and pitches (different types of sound) being transmitted from the sensory receptors of the ears.
Primary visual cortex, sight, reading and visual images
Visual cortex
Visual Agnosia
Hallucinations, cortical blindness
Prosopagnosia
Inability to recognize familiar faces
Simultanagnosia
Can’t see more than one thing or aspect of object at a time
Professor Yang Dan at UC Berkeley demonstrates the technology that captures images of what a cat sees. This is one approach to the technical challenge to remotely acquire the vision of an animal.
http://news.bbc.co.uk/1/hi/sci/tech/4...
(2001) Dr José Manuel Rodriguez Delgado states in an interview on electromagnetic fields and their effect on people. "I could later do with electro-magnetic radiation what I did with the stimoceiver. It's much better because there's no need for surgery,"
http://www.cabinetmagazine.org/issues...