Neuro Guidelines Chap 7 - Perinatal Studies

Question 1

which species is studied the most for development of pain perception?

Answer 1

Rat

Question 2

At what gestational age do fetuses respond to noxious stimuli in various species, rat, lamb, NHP?

Answer 2

Rat=d17, Lamb=125d, Rhesus d133

Question 3

At what age does a rat fetus respond to formalin injection into the paw?

Answer 3

embryonic day 19 with c-fos expression in spinal cord at E20

Question 4

How early is allodynia noted in rat pups post-natally with experimentally induced inflammation?

Answer 4

3d

Question 5

Behavioral responses to induced inflammation are noted at what age in rat pups?

Answer 5

1d

Question 6

At what age are mature pain responses noted in rats?

Answer 6

3 weeks (weaning)

Question 7

What differences in neonates are present that can affect pharmacokinetics and pharmacodynamics of analgesics and anesthetics?

Answer 7

Permeable blood-brain-barrier, higher body water content, lower albumin, immature hepatic microsomal enzymes

Question 8

At what point of gestation should management of pain be considered for the fetus?

Answer 8

Late-term gestation many species are noted to respond to noxious stimuli.

Question 9

For fetal procedures of late term gestation, is the analgesia and anesthetics provided to the dam sufficient for the fetus?

Answer 9

yes, most drug classes cross the placenta

Question 10

How do rodent neonates differ from more precocious or large species neonates in the use of anesthetics and analgesics?

Answer 10

rodent neonates are much more sensitive to the side effects of analgesics like ketamine and pentobarbital while precocious animals and large species neonates are not.

Question 11

What anesthetic techniques have provided the best results for neonatal rodents?

Answer 11

inhalants and hypothermia

Question 12

What is the first choice of anesthetic for neonatal rodents?

Answer 12

inhalants and if not feasible then hypothermia

Question 13

At what age is hypothermia recommended for neonatal rodent anesthesia?

Answer 13

up to 7d of age

Question 14

With which anesthetic technique do rat pups emit ultrasonic vocalizations even after being returned to their dams?

Answer 14

hypothermia, recommend to insulate them

Question 15

How is anesthetic depth assessed in neonatal rodents?

Answer 15

Similar to adults, toe or tail pinch.

Question 16

Opioid analgesics are effective against which types of pain in neonatal rodents?

Answer 16

mechanical, inflammatory, thermal

Question 17

What methods can be used to decrease cannabalism after returning neonatal rodents to the dam?

Answer 17

Make sure they are fully recovered, place them in the middle of the litter, allow them time to settle in before returning dam to litter, smear them with urine/feces/bedding from the cage, foster the litter to an outbred strain that has similar aged litter for a few hours to overnight.

Question 18

What scented substances can be used to aid with reintroduction of rodent neonates to their dams post operatively?

Answer 18

Vicks Vapo-rub or baby powder

Question 19

Describe the technique for cross fostering of pups/litters for pups involved in research protocols requiring removal from the dam.

Answer 19

Similar aged litter of the protocol litter is removed from the dam and swapped with litter of a strain/stock that is known to have good maternal care. Return the neonates undergoing surgery to their litter and foster dam for a few hours or overnight. Once neonates are fully recovered, return litter to original dam.

Question 20

What strain of mouse is known for high cannabalism rates of litters that undergoing surgical procedures?

Answer 20

BALB/c

Question 21

What does The Guide recommend regarding toe clipping of neonatal rodents?

Answer 21

It may be the preferred method, as it shows no adverse effects on behavior and well being at 7d of age or younger. (pg 75). However, The Guide does say it should be used when other methods are not feasible.

Question 22

At what age is toe clipping recommended based on The Guide

Answer 22

7d or less (same ages for hypothermia listed in Neuroscience guidelines)

Question 23

For neuroscience procedures on fetuses of large species that need to be performed in a lab setting instead of a dedicated surgical facility, how does the research institution handle this?

Answer 23

the IACUC should provide approval for the scientific justfication. Neuroscience guidelines recommend a team approach with IACUC, DVM, PI using performance standards to guide appropriate care of the animals.

Question 24

Rodent fetuses of what gestation can be left in the uterus for euthanasia after the dam has been euthanized?

Answer 24

Embryonic day 14, lack of neural development prevents response to noxious stimuli. AVMA Euth Guidelines say leave them in uterus, no specific age is listed.