Flashcards in Week 2 Fetal and Neurologic Injury (everything) Deck (66)
The brain continuously evolves during development (egg to death) but it is susceptible to subtle changes in the
internal and external milieu
Neurologic injury is most dynamic during what period of fetal life/growth?
detection and diagnosis of fetal and neonatal brain injury have been advanced by:
functional imaging and the identification of potential biochemical markers
What mediators play an important role in the pathophysiology of fetal brain injury?
maternal administration of ___ before preterm birth reduces the risk of what?
- cerebral palsy
Induced hypothermia is beneficial for the treatment of (neonatal)
rodent and primate data suggest that fetal exposure to anesthetic agents may have harmful effects on
neurogenesis and synapse development in the developing brain.
**What are the three major events that appear critical to the establishment of functional synapses:
1. Neuronal proliferation
3. cellular differentiation
**Neurogenesis beings with
neural stem/progenitor cells in neurogenic niches such as:
-subventricular and the subgranular zone of the dentate gyrus
**Neurogenesis is a term that encompasses both
Neuronal proliferation and subsequent survival
(begins w/neural stem/progenitor cells in neurogenic niches such as the subventricular zone and the subgranular zone of the dentate gyrus.
Neural progenitor cells undergo ____ to generate immature neurons to "laminate the cortex"
Immature neurons are generated during :
**Interneurons compose what % of the total neuronal cells in the brain?
Interneurons originate from the
ganglionic eminences in the developing brain
**The two Neurotransmitters important for fetal brain development:
GABA and Glutamate
*Neurogenesis starts at ____ weeks gestation
*Neurogenesis peaks at ___ weeks gestation
*Neuronal migration is completed between how many weeks gestation:
Synapse formation begins as early as
10 wks and continues to increase gradually at a rate of ~ 4%/week until the end of second trimester
A robust increase in synapse formation (40,000 synapses/min) occurs bw :
28wks and term gestation
Neurogenesis and synapse formation occur in conjunction w/the onset of
-- result in a 5-fold increase in brain volume and appearance of mature brain features such as sulci and gyri
***By 24 wks the fetus has all the neural machinery necessary to
perceive pain **
B/c at 24 wks the fetus can perceive pain, many clinicians recommend
appropriate measures should be taken to provide fetal analgesia during fetal surgical procedures from this pt onward
Among the NT's, which remains the most widely studied?
How does GABA action compare in the mature brain vs the developing fetal brain?
GABA has an inhibitory action in the mature brain.
GABA serves an EXCITATORY role during fetal brain development.
The major mechanism for the GABA role reversal (mature vs fetal brain) is differential expression of
Chloride ion transporters (NKCC1 and KCC2)
the chloride ion transporters increase
intracellular concentration of Chloride in developing neurons.
Stimulated GABA receptors in neural progenitor cells and immature neurons, chloride ions cause
membrane DEPOLARIZATION rather than the HYPERPOLARIZATION seen in mature neurons.
** The depolarizing effect of GABA decreases