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 start with a single cell that begins to divide!.

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Presentation on theme: " start with a single cell that begins to divide!."— Presentation transcript:

1  start with a single cell that begins to divide!

2  Gives rise to neural tube (which gives rise to the CNS)

3  What determines what and where a neuron should be? ◦ very complicated – numerous models; pluripotent (versatile) to begin with ◦ role of nearby chemical factors that can influence things

4  cortex has multiple layers with different size/shape neurons -  radial glia in cortex

5  growth cones and “lamellipodia”  cell attractants and repellants

6  Once neuron reaches destination; it needs to ◦ form synaptic connections ◦ make neurotransmitter ◦ elongate its axon ◦ make postsynaptic and presynaptic receptors ◦ JUST TO NAME A FEW THINGS!!!

7  apoptosis – “programmed cell death” ◦ what controls apoptosis  many things!  activity  drugs?  environment?

8  two disorders where brain development does not go quite as planned  autism and Fetal Alcohol Syndrome ◦ similar in that these both involve changes in brain during developmental; ◦ developmental disorders  differences ◦ one is preventable!

9  characteristics: ◦ Delayed or unusual speech patterns ◦ High pitched or flat intonation ◦ Lack of slang or "kidspeak" ◦ Difficulty understanding tone of voice and body language as a way of expressing sarcasm, humor, irony, etc. ◦ Lack of eye contact ◦ Inability to take another's perspective (to imagine oneself in someone else's shoes) ◦ hypo or hypersensitive to environmental stimuli

10  Engage in repetitive behaviors and ritualized activities, ranging from lining up items to following a rigid routine; OCD symptoms  Have one or a few passionate interests,  Have difficulty in making and keeping multiple friends,  Prefer activities that require relatively little verbal interaction.

11  possible deficits in complex or higher order cognitive abilities  evoked potentials ◦ auditory and visual ERPs altered  processing of emotional facial expressions ◦ - ERPs

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14  Teratogen: a substance capable of interfering with fetal development  Teratology: the biological study of birth defects  Behavioral Teratology: the study of how agents can affect behavior (so affects brain)

15 Teratogen Historical View of Alcohol as a Teratogen “ “Foolish, drunken, or harebrain women most often bring forth children like unto themselves” Aristotle in Problemata “Behold, thou shalt conceive and bear a son: And now, drink no wine or strong drink.” Judges 13:7

16 “… the idea of germ poisoning by alcohol in humans may be safely dismissed…” Journal of Studies on Alcohol, 1, 1940 “The offspring of alcoholics have been found defective not because of alcoholism of the parents but because the parents themselves came from a defective stock.” Journal American Medical Association, 132:419, 1946 Ethanol drip was used to treat premature labor. 1973: First scientific paper naming Fetal Alcohol Syndrome Alcohol as a Teratogen: 20 th Century

17 Fetal Alcohol Syndrome Fetal alcohol syndrome is the leading preventable cause of mental retardation. What is it, how does it affect people, what can we do about it?

18 Fetal Alcohol Syndrome: Diagnostic Criteria Pre- and/or postnatal growth deficiency Evidence of central nervous system dysfunction Specific pattern of facial features

19 Streissguth, 1994 FAS: Characteristic Facial Features

20 FAS – Only the tip of the iceberg Fetal alcohol syndrome Fetal alcohol syndrome Fetal alcohol effects Fetal alcohol effects Clinical suspect but appear normal Clinical suspect but appear normal Normal, but never reach their potential Normal, but never reach their potential Adapted from Streissguth

21 ARND: Alcohol-Related Neurodevelopmental Disorder ARBD: Alcohol-Related Birth Defects

22 ◦ Approximately 1 FAS birth out of 1000 live births in the US  Approximately 3-6 FASD births out of 1000 live births in the US ◦ Estimated costs 2.8 billion/year

23  The sole cause of FASD is women drinking alcoholic beverages during pregnancy.  Alcohol is a teratogen. “Of all the substances of abuse (including cocaine, heroin, and marijuana), alcohol produces by far the most serious neurobehavioral effects in the fetus.” —IOM Report to Congress, 1996.

24  more than 130,000 pregnant women/yr in US drink at levels that may increase risk of FAS  rates of frequent and binge drinking in pregnant women have NOT declined in the last 8 years

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26 FSIQVIQPIQ 40 55 70 85 100 115 Standard score IQ scale NC PEA FAS * * * ** * * General Intellectual Performance

27 2 1 3 1 2 3 Group 0 2 4 6 Rule Violations NC PEA FAS P<0.001 Move only one piece at a time using one hand and never place a big piece on top of a little piece Starting position Ending position Mattson, et al., 1999 Executive functioning deficits

28  hyperactivity, response inhibition deficits, attentional problems, motor coordination deficits, executive function (planning) problems,

29  Poor judgement  Attention deficits  Arithmetic disabilities  Memory deficits  Problems with abstract thought  Impulsivity  Easily victimized  unfocused or distractible  difficulty handling $$  difficulty learning from experience  difficulty under- standing consequences  poor frustration tolerance

30  = Age 6+  = Age 12+  = Age 21+ Percent of Persons With FAS or FAE Who Had Secondary Disabilities

31  plenty of data ◦ cerebellum ◦ cerebral cortex ◦ corpus callosum ◦ basal ganglia

32 photo: Clarren, 1986

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34 *** ** CerebrumCerebellum 75 80 85 90 95 100 PEA FAS <p 0.001 p < 0.010 Cerebrum Cerebellum Corpus Callosum Mattson et al., 1994

35 Mattson, et al., 1994; Mattson & Riley, 1995; Riley et al., 1995

36 Risk Factors Dose of alcohol Pattern of exposure - binge vs chronic Genetics Maternal characteristics Reactions with other drugs Nutrition Developmental timing of exposure

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38  Growth retardation  Facial characteristics  Heart, skeletal defects  Microcephaly  Reductions in basal ganglia and cerebellar volumes  Callosal anomalies  Hyperactivity, attentional problems  Inhibitory deficits  Impaired learning  Perseveration errors  Feeding difficulties  Gait anomalies  Hearing anomalies Driscoll, et al., 1990; Samson, 1986;

39 Hyperactivity Motor Deficits

40  protective factors ◦ interventions and stable environment and guardianship (for kids as they grow up) ◦ numerous programs exist – maybe not enough but progress is being made

41  environmental enrichment

42  Reduces many of the behavioral deficits reported  increases dendritic spines (in controls and drug treated)

43  drugs that ◦ increase cholinergic activity ◦ reduce glutamate activity  just naming a few – seem to reduce some of alcohol’s effects on the developing brain


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