Abstract
The genetically hypothyroid mouse, Tshrhyt, has a single point mutation resulting in a defective thyroid-stimulating hormone receptor, and therefore a non-functional thyroid gland. This is an autosomal recessive disorder and affected mice have been reported to have a number of somatic and behavioral deficits. This study reports a pronounced, spontaneous, asymmetrical circling behavior in the Tshrhyt mouse. The spontaneous circling behavior appeared in about 25% of the homozygous animals, in both males and females. The circling usually appeared by postnatal day 35 and continued throughout the lifespan of the animal. The circling was in one direction only, either clockwise or counterclockwise, with the directional preference being almost absolute. A stereological analysis of tyrosine hydroxylase immunoreactive neurons in the substantia nigra and adjacent ventral tegmental area of circling homozygous mice, non-circling homozygous mice and heterozygous mice revealed that the circlers had significantly fewer (40% reduction) midbrain dopamine neurons than those animals that did not circle. There was not an association between the direction of the circling and an asymmetry in the number of dopamine neurons in the midbrains of these mice. There was no difference in the number of dopamine neurons in the midbrain of the homozygous non-circlers and the heterozygous mice. These studies indicate that about 25% of genetically hypothyroid mice demonstrated a spontaneous, perseverative, unilateral circling behavior that was associated with a significant reduction in the number of their midbrain dopamine neurons. Thus congenitally hypothyroid mice are at risk for a reduction in the number of nigral dopamine neurons and an associated repetitive movement disorder.
| Original language | English |
|---|---|
| Pages (from-to) | 891-898 |
| Number of pages | 8 |
| Journal | Neuroscience |
| Volume | 105 |
| Issue number | 4 |
| DOIs | |
| State | Published - Aug 22 2001 |
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All Science Journal Classification (ASJC) codes
- Neuroscience(all)
Cite this
Spontaneous circling behavior and dopamine neuron loss in a genetically hypothyroid mouse. / Kincaid, Anthony.
In: Neuroscience, Vol. 105, No. 4, 22.08.2001, p. 891-898.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Spontaneous circling behavior and dopamine neuron loss in a genetically hypothyroid mouse
AU - Kincaid, Anthony
PY - 2001/8/22
Y1 - 2001/8/22
N2 - The genetically hypothyroid mouse, Tshrhyt, has a single point mutation resulting in a defective thyroid-stimulating hormone receptor, and therefore a non-functional thyroid gland. This is an autosomal recessive disorder and affected mice have been reported to have a number of somatic and behavioral deficits. This study reports a pronounced, spontaneous, asymmetrical circling behavior in the Tshrhyt mouse. The spontaneous circling behavior appeared in about 25% of the homozygous animals, in both males and females. The circling usually appeared by postnatal day 35 and continued throughout the lifespan of the animal. The circling was in one direction only, either clockwise or counterclockwise, with the directional preference being almost absolute. A stereological analysis of tyrosine hydroxylase immunoreactive neurons in the substantia nigra and adjacent ventral tegmental area of circling homozygous mice, non-circling homozygous mice and heterozygous mice revealed that the circlers had significantly fewer (40% reduction) midbrain dopamine neurons than those animals that did not circle. There was not an association between the direction of the circling and an asymmetry in the number of dopamine neurons in the midbrains of these mice. There was no difference in the number of dopamine neurons in the midbrain of the homozygous non-circlers and the heterozygous mice. These studies indicate that about 25% of genetically hypothyroid mice demonstrated a spontaneous, perseverative, unilateral circling behavior that was associated with a significant reduction in the number of their midbrain dopamine neurons. Thus congenitally hypothyroid mice are at risk for a reduction in the number of nigral dopamine neurons and an associated repetitive movement disorder.
AB - The genetically hypothyroid mouse, Tshrhyt, has a single point mutation resulting in a defective thyroid-stimulating hormone receptor, and therefore a non-functional thyroid gland. This is an autosomal recessive disorder and affected mice have been reported to have a number of somatic and behavioral deficits. This study reports a pronounced, spontaneous, asymmetrical circling behavior in the Tshrhyt mouse. The spontaneous circling behavior appeared in about 25% of the homozygous animals, in both males and females. The circling usually appeared by postnatal day 35 and continued throughout the lifespan of the animal. The circling was in one direction only, either clockwise or counterclockwise, with the directional preference being almost absolute. A stereological analysis of tyrosine hydroxylase immunoreactive neurons in the substantia nigra and adjacent ventral tegmental area of circling homozygous mice, non-circling homozygous mice and heterozygous mice revealed that the circlers had significantly fewer (40% reduction) midbrain dopamine neurons than those animals that did not circle. There was not an association between the direction of the circling and an asymmetry in the number of dopamine neurons in the midbrains of these mice. There was no difference in the number of dopamine neurons in the midbrain of the homozygous non-circlers and the heterozygous mice. These studies indicate that about 25% of genetically hypothyroid mice demonstrated a spontaneous, perseverative, unilateral circling behavior that was associated with a significant reduction in the number of their midbrain dopamine neurons. Thus congenitally hypothyroid mice are at risk for a reduction in the number of nigral dopamine neurons and an associated repetitive movement disorder.
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U2 - 10.1016/S0306-4522(01)00229-9
DO - 10.1016/S0306-4522(01)00229-9
M3 - Article
VL - 105
SP - 891
EP - 898
JO - Neuroscience
JF - Neuroscience
SN - 0306-4522
IS - 4
ER -