Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal...
Transcript of Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal...
![Page 1: Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal Development of the Rat. Part I Catherine Picut, VMD, JD, DACVP, DABT catherine.picut@crl.com](https://reader034.fdocuments.in/reader034/viewer/2022043022/5f3e3bca7d1e83496826572f/html5/thumbnails/1.jpg)
•
Histology of Postnatal
Development of the Rat.
Part I
Catherine Picut, VMD, JD, DACVP, DABT
IATP-ESTP 20Sept2016
![Page 2: Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal Development of the Rat. Part I Catherine Picut, VMD, JD, DACVP, DABT catherine.picut@crl.com](https://reader034.fdocuments.in/reader034/viewer/2022043022/5f3e3bca7d1e83496826572f/html5/thumbnails/2.jpg)
Outline of Presentation
• Microscopic Development of Selected Tissues
- Brain, Testis, Ovary, Lung, Thyroid
- Point out: critical time points, diagnostic
pitfalls, & biologically interesting features
![Page 3: Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal Development of the Rat. Part I Catherine Picut, VMD, JD, DACVP, DABT catherine.picut@crl.com](https://reader034.fdocuments.in/reader034/viewer/2022043022/5f3e3bca7d1e83496826572f/html5/thumbnails/3.jpg)
Post-natal developmental stages
Stage Rat Human
Neonatal 0 - 7 d 0 – 28 days
Infantile 8 – 20 d 1 – 23 months
Juvenile 21 – 32 d 2 – 12 years
Peripubertal 33 – 55 d 13 – 16 years
![Page 4: Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal Development of the Rat. Part I Catherine Picut, VMD, JD, DACVP, DABT catherine.picut@crl.com](https://reader034.fdocuments.in/reader034/viewer/2022043022/5f3e3bca7d1e83496826572f/html5/thumbnails/4.jpg)
Brain
![Page 5: Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal Development of the Rat. Part I Catherine Picut, VMD, JD, DACVP, DABT catherine.picut@crl.com](https://reader034.fdocuments.in/reader034/viewer/2022043022/5f3e3bca7d1e83496826572f/html5/thumbnails/5.jpg)
Changes in composition of brain
•
Cortical neurons
0 7 14 21 … 37
Cerebellar &
Hippocampal
& Olfactory
Bulb neurons
Postnatal days in rat
Number
Human brain at birth
![Page 6: Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal Development of the Rat. Part I Catherine Picut, VMD, JD, DACVP, DABT catherine.picut@crl.com](https://reader034.fdocuments.in/reader034/viewer/2022043022/5f3e3bca7d1e83496826572f/html5/thumbnails/6.jpg)
PND 1 Brain 1.25x
![Page 7: Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal Development of the Rat. Part I Catherine Picut, VMD, JD, DACVP, DABT catherine.picut@crl.com](https://reader034.fdocuments.in/reader034/viewer/2022043022/5f3e3bca7d1e83496826572f/html5/thumbnails/7.jpg)
PND 21 cerebellum
![Page 8: Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal Development of the Rat. Part I Catherine Picut, VMD, JD, DACVP, DABT catherine.picut@crl.com](https://reader034.fdocuments.in/reader034/viewer/2022043022/5f3e3bca7d1e83496826572f/html5/thumbnails/8.jpg)
Secondary Germinal Matrix
Purkinje
Granular Cell
Primary Germinal Matrix
4th Ventricle
Pia
Development of the Layers of the Cerebellum
![Page 9: Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal Development of the Rat. Part I Catherine Picut, VMD, JD, DACVP, DABT catherine.picut@crl.com](https://reader034.fdocuments.in/reader034/viewer/2022043022/5f3e3bca7d1e83496826572f/html5/thumbnails/9.jpg)
PND 1 Cerebellum
![Page 10: Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal Development of the Rat. Part I Catherine Picut, VMD, JD, DACVP, DABT catherine.picut@crl.com](https://reader034.fdocuments.in/reader034/viewer/2022043022/5f3e3bca7d1e83496826572f/html5/thumbnails/10.jpg)
PND 7 cerebellum 40x
![Page 11: Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal Development of the Rat. Part I Catherine Picut, VMD, JD, DACVP, DABT catherine.picut@crl.com](https://reader034.fdocuments.in/reader034/viewer/2022043022/5f3e3bca7d1e83496826572f/html5/thumbnails/11.jpg)
PND 14 cerebelllum
![Page 12: Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal Development of the Rat. Part I Catherine Picut, VMD, JD, DACVP, DABT catherine.picut@crl.com](https://reader034.fdocuments.in/reader034/viewer/2022043022/5f3e3bca7d1e83496826572f/html5/thumbnails/12.jpg)
PND 21 cerebellum
![Page 13: Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal Development of the Rat. Part I Catherine Picut, VMD, JD, DACVP, DABT catherine.picut@crl.com](https://reader034.fdocuments.in/reader034/viewer/2022043022/5f3e3bca7d1e83496826572f/html5/thumbnails/13.jpg)
PND 1 Cortex: motor
![Page 14: Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal Development of the Rat. Part I Catherine Picut, VMD, JD, DACVP, DABT catherine.picut@crl.com](https://reader034.fdocuments.in/reader034/viewer/2022043022/5f3e3bca7d1e83496826572f/html5/thumbnails/14.jpg)
PND 7: Cortex: motor
![Page 15: Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal Development of the Rat. Part I Catherine Picut, VMD, JD, DACVP, DABT catherine.picut@crl.com](https://reader034.fdocuments.in/reader034/viewer/2022043022/5f3e3bca7d1e83496826572f/html5/thumbnails/15.jpg)
PND 6 Brain: motor Caspase-3 40x
![Page 16: Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal Development of the Rat. Part I Catherine Picut, VMD, JD, DACVP, DABT catherine.picut@crl.com](https://reader034.fdocuments.in/reader034/viewer/2022043022/5f3e3bca7d1e83496826572f/html5/thumbnails/16.jpg)
PND 7 Deep Cerebellar Nucleus
![Page 17: Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal Development of the Rat. Part I Catherine Picut, VMD, JD, DACVP, DABT catherine.picut@crl.com](https://reader034.fdocuments.in/reader034/viewer/2022043022/5f3e3bca7d1e83496826572f/html5/thumbnails/17.jpg)
PND 21 cortex (motor) 20x
![Page 18: Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal Development of the Rat. Part I Catherine Picut, VMD, JD, DACVP, DABT catherine.picut@crl.com](https://reader034.fdocuments.in/reader034/viewer/2022043022/5f3e3bca7d1e83496826572f/html5/thumbnails/18.jpg)
Choroid Plexus PND 1 (vacuolated)
![Page 19: Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal Development of the Rat. Part I Catherine Picut, VMD, JD, DACVP, DABT catherine.picut@crl.com](https://reader034.fdocuments.in/reader034/viewer/2022043022/5f3e3bca7d1e83496826572f/html5/thumbnails/19.jpg)
Brain – summarized points
• Neurons are developed by time of birth
• Postnatal development of neurons limited to:
– Cerebellum (granular cell layer)
– Olfactory Bulbs
– Hippocampus
• Apoptosis of cortical neurons is normal from PND
1 – PND 14 (Peak around PND 7)
• Vacuolation of choroid plexus is normal from birth
to about PND 14.
![Page 20: Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal Development of the Rat. Part I Catherine Picut, VMD, JD, DACVP, DABT catherine.picut@crl.com](https://reader034.fdocuments.in/reader034/viewer/2022043022/5f3e3bca7d1e83496826572f/html5/thumbnails/20.jpg)
TESTES
![Page 21: Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal Development of the Rat. Part I Catherine Picut, VMD, JD, DACVP, DABT catherine.picut@crl.com](https://reader034.fdocuments.in/reader034/viewer/2022043022/5f3e3bca7d1e83496826572f/html5/thumbnails/21.jpg)
180 46
Postnatal day
Spermatogonia
Sertoli cells
BTB
First Wave of Spermatogenesis
Uniform Tubules / No Staging
Unique Cell Types
Unique Cell Distribution
![Page 22: Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal Development of the Rat. Part I Catherine Picut, VMD, JD, DACVP, DABT catherine.picut@crl.com](https://reader034.fdocuments.in/reader034/viewer/2022043022/5f3e3bca7d1e83496826572f/html5/thumbnails/22.jpg)
Testis PND 3 (Neonatal) 40x
![Page 23: Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal Development of the Rat. Part I Catherine Picut, VMD, JD, DACVP, DABT catherine.picut@crl.com](https://reader034.fdocuments.in/reader034/viewer/2022043022/5f3e3bca7d1e83496826572f/html5/thumbnails/23.jpg)
PND 9 (Early Infantile)
![Page 24: Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal Development of the Rat. Part I Catherine Picut, VMD, JD, DACVP, DABT catherine.picut@crl.com](https://reader034.fdocuments.in/reader034/viewer/2022043022/5f3e3bca7d1e83496826572f/html5/thumbnails/24.jpg)
Testis PND 15 (Late Infantile) 57x
![Page 25: Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal Development of the Rat. Part I Catherine Picut, VMD, JD, DACVP, DABT catherine.picut@crl.com](https://reader034.fdocuments.in/reader034/viewer/2022043022/5f3e3bca7d1e83496826572f/html5/thumbnails/25.jpg)
PND 18 Testis PAS stain 60x
L
![Page 26: Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal Development of the Rat. Part I Catherine Picut, VMD, JD, DACVP, DABT catherine.picut@crl.com](https://reader034.fdocuments.in/reader034/viewer/2022043022/5f3e3bca7d1e83496826572f/html5/thumbnails/26.jpg)
PND 27 (Juvenile): Normal apoptosis
![Page 27: Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal Development of the Rat. Part I Catherine Picut, VMD, JD, DACVP, DABT catherine.picut@crl.com](https://reader034.fdocuments.in/reader034/viewer/2022043022/5f3e3bca7d1e83496826572f/html5/thumbnails/27.jpg)
PND 28 Testis/Epididymis; Exfoliation
![Page 28: Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal Development of the Rat. Part I Catherine Picut, VMD, JD, DACVP, DABT catherine.picut@crl.com](https://reader034.fdocuments.in/reader034/viewer/2022043022/5f3e3bca7d1e83496826572f/html5/thumbnails/28.jpg)
Summary about Testis
Apoptosis is normal in
– late infantile period (PND 15-18)
– juvenile period (PND 27)
– Don’t confuse early spermatocytes with necrosis
Critical Window (PND 5 – 15)
-- significant, uniform, susceptible cell populations.
Unique cell distributions (PND 0 - PND 30)
![Page 29: Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal Development of the Rat. Part I Catherine Picut, VMD, JD, DACVP, DABT catherine.picut@crl.com](https://reader034.fdocuments.in/reader034/viewer/2022043022/5f3e3bca7d1e83496826572f/html5/thumbnails/29.jpg)
OVARY
![Page 30: Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal Development of the Rat. Part I Catherine Picut, VMD, JD, DACVP, DABT catherine.picut@crl.com](https://reader034.fdocuments.in/reader034/viewer/2022043022/5f3e3bca7d1e83496826572f/html5/thumbnails/30.jpg)
Ovary. PND 13: “Atypical” follicles
are normal
![Page 31: Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal Development of the Rat. Part I Catherine Picut, VMD, JD, DACVP, DABT catherine.picut@crl.com](https://reader034.fdocuments.in/reader034/viewer/2022043022/5f3e3bca7d1e83496826572f/html5/thumbnails/31.jpg)
Ovary PND 27 Atresia
![Page 32: Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal Development of the Rat. Part I Catherine Picut, VMD, JD, DACVP, DABT catherine.picut@crl.com](https://reader034.fdocuments.in/reader034/viewer/2022043022/5f3e3bca7d1e83496826572f/html5/thumbnails/32.jpg)
PND 35 Ovary
![Page 33: Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal Development of the Rat. Part I Catherine Picut, VMD, JD, DACVP, DABT catherine.picut@crl.com](https://reader034.fdocuments.in/reader034/viewer/2022043022/5f3e3bca7d1e83496826572f/html5/thumbnails/33.jpg)
Picut C A et al. Toxicol Pathol 2013;42:403-413
PND 20 PND 25
PND 29 PND 32
PND32
RAT: VAGINA
![Page 34: Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal Development of the Rat. Part I Catherine Picut, VMD, JD, DACVP, DABT catherine.picut@crl.com](https://reader034.fdocuments.in/reader034/viewer/2022043022/5f3e3bca7d1e83496826572f/html5/thumbnails/34.jpg)
Summary about Ovary
– Atypical follicles in young animal are normal (PND 10-
16).
– Apoptosis/atresia is normal in late juvenile period (PND
26-28)
– Corpora lutea >PND35
– The vagina will “mature” prior than the ovary.
![Page 35: Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal Development of the Rat. Part I Catherine Picut, VMD, JD, DACVP, DABT catherine.picut@crl.com](https://reader034.fdocuments.in/reader034/viewer/2022043022/5f3e3bca7d1e83496826572f/html5/thumbnails/35.jpg)
Thyroid Gland
![Page 36: Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal Development of the Rat. Part I Catherine Picut, VMD, JD, DACVP, DABT catherine.picut@crl.com](https://reader034.fdocuments.in/reader034/viewer/2022043022/5f3e3bca7d1e83496826572f/html5/thumbnails/36.jpg)
Thyroid Gland
• Thyroid gland is histologically mature by PND 7
• Thyroid Gland in rat at birth is equivalent to a
human at 5 months of pregnancy.
• Most dramatic changes occur GD 20 – PND 5
![Page 37: Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal Development of the Rat. Part I Catherine Picut, VMD, JD, DACVP, DABT catherine.picut@crl.com](https://reader034.fdocuments.in/reader034/viewer/2022043022/5f3e3bca7d1e83496826572f/html5/thumbnails/37.jpg)
GD 20 PND 3 PND 10-30
![Page 38: Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal Development of the Rat. Part I Catherine Picut, VMD, JD, DACVP, DABT catherine.picut@crl.com](https://reader034.fdocuments.in/reader034/viewer/2022043022/5f3e3bca7d1e83496826572f/html5/thumbnails/38.jpg)
Thyroid Gland PND 15
male
female
![Page 39: Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal Development of the Rat. Part I Catherine Picut, VMD, JD, DACVP, DABT catherine.picut@crl.com](https://reader034.fdocuments.in/reader034/viewer/2022043022/5f3e3bca7d1e83496826572f/html5/thumbnails/39.jpg)
Epithelial cell height
![Page 40: Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal Development of the Rat. Part I Catherine Picut, VMD, JD, DACVP, DABT catherine.picut@crl.com](https://reader034.fdocuments.in/reader034/viewer/2022043022/5f3e3bca7d1e83496826572f/html5/thumbnails/40.jpg)
Thyroid Gland PND 42 Male
![Page 41: Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal Development of the Rat. Part I Catherine Picut, VMD, JD, DACVP, DABT catherine.picut@crl.com](https://reader034.fdocuments.in/reader034/viewer/2022043022/5f3e3bca7d1e83496826572f/html5/thumbnails/41.jpg)
Lung
![Page 42: Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal Development of the Rat. Part I Catherine Picut, VMD, JD, DACVP, DABT catherine.picut@crl.com](https://reader034.fdocuments.in/reader034/viewer/2022043022/5f3e3bca7d1e83496826572f/html5/thumbnails/42.jpg)
Development of Lung in Rat
![Page 43: Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal Development of the Rat. Part I Catherine Picut, VMD, JD, DACVP, DABT catherine.picut@crl.com](https://reader034.fdocuments.in/reader034/viewer/2022043022/5f3e3bca7d1e83496826572f/html5/thumbnails/43.jpg)
http://www.ana.unibe.ch/users/schittny/public_html/Reprints/Schittny2008Fishman.pdf
saccular
Alveolar “Double
capillary” “Single
capillary” due
to merging of
capillaries
![Page 44: Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal Development of the Rat. Part I Catherine Picut, VMD, JD, DACVP, DABT catherine.picut@crl.com](https://reader034.fdocuments.in/reader034/viewer/2022043022/5f3e3bca7d1e83496826572f/html5/thumbnails/44.jpg)
Lung PND1 Saccular Stage
![Page 45: Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal Development of the Rat. Part I Catherine Picut, VMD, JD, DACVP, DABT catherine.picut@crl.com](https://reader034.fdocuments.in/reader034/viewer/2022043022/5f3e3bca7d1e83496826572f/html5/thumbnails/45.jpg)
Lung PND 14 Bulk Alveolarization
![Page 46: Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal Development of the Rat. Part I Catherine Picut, VMD, JD, DACVP, DABT catherine.picut@crl.com](https://reader034.fdocuments.in/reader034/viewer/2022043022/5f3e3bca7d1e83496826572f/html5/thumbnails/46.jpg)
Lung PND 15 “bulk alveolarization”
![Page 47: Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal Development of the Rat. Part I Catherine Picut, VMD, JD, DACVP, DABT catherine.picut@crl.com](https://reader034.fdocuments.in/reader034/viewer/2022043022/5f3e3bca7d1e83496826572f/html5/thumbnails/47.jpg)
PND 21 (mature septae)
![Page 48: Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal Development of the Rat. Part I Catherine Picut, VMD, JD, DACVP, DABT catherine.picut@crl.com](https://reader034.fdocuments.in/reader034/viewer/2022043022/5f3e3bca7d1e83496826572f/html5/thumbnails/48.jpg)
![Page 49: Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal Development of the Rat. Part I Catherine Picut, VMD, JD, DACVP, DABT catherine.picut@crl.com](https://reader034.fdocuments.in/reader034/viewer/2022043022/5f3e3bca7d1e83496826572f/html5/thumbnails/49.jpg)
Issues/Concern about Lung
• Immature lung could be confused with interstitial
pneumonia or atelectasis. Elastin stains may
help identify immaturity.
• Hyperoxia can cause “delayed maturation” of
lung (animal model for premature births).
• Steroids/retinoids can cause “precocious”
maturation of lung – interstitium thins but doesn’t
septate properly
![Page 50: Histology of Postnatal Development of the Rat. Part I · 2018-05-22 · Histology of Postnatal Development of the Rat. Part I Catherine Picut, VMD, JD, DACVP, DABT catherine.picut@crl.com](https://reader034.fdocuments.in/reader034/viewer/2022043022/5f3e3bca7d1e83496826572f/html5/thumbnails/50.jpg)
End of Part I