Limits...
Enhanced functional connectivity involving the ventromedial hypothalamus following methamphetamine exposure.

Zuloaga DG, Iancu OD, Weber S, Etzel D, Marzulla T, Stewart B, Allen CN, Raber J - Front Neurosci (2015)

Bottom Line: MA phase shifts, entrains the circadian clock and can also alter the entraining effect of light by currently unknown mechanisms.There were five distinct patterns of neuronal activation.Functional connectivity between the ventromedial hypothalamus (VMH) and other brain areas, including the paraventricular nucleus of the hypothalamus and basolateral and medial amygdala, was enhanced following MA exposure, suggesting a role for the VMH in the effects of MA on the brain.

View Article: PubMed Central - PubMed

Affiliation: Department of Behavioral Neuroscience, Oregon Health & Science University Portland Portland, OR, USA ; Department of Psychology, University at Albany Albany, NY, USA.

ABSTRACT
Methamphetamine (MA) consumption causes disruption of many biological rhythms including the sleep-wake cycle. This circadian effect is seen shortly following MA exposure and later in life following developmental MA exposure. MA phase shifts, entrains the circadian clock and can also alter the entraining effect of light by currently unknown mechanisms. We analyzed and compared immunoreactivity of the immediate early gene c-Fos, a marker of neuronal activity, to assess neuronal activation 2 h following MA exposure in the light and dark phases. We used network analyses of correlation patterns derived from global brain immunoreactivity patterns of c-Fos, to infer functional connectivity between brain regions. There were five distinct patterns of neuronal activation. In several brain areas, neuronal activation following exposure to MA was stronger in the light than the dark phase, highlighting the importance of considering circadian periods of increased effects of MA in defining experimental conditions and understanding the mechanisms underlying detrimental effects of MA exposure to brain function. Functional connectivity between the ventromedial hypothalamus (VMH) and other brain areas, including the paraventricular nucleus of the hypothalamus and basolateral and medial amygdala, was enhanced following MA exposure, suggesting a role for the VMH in the effects of MA on the brain.

No MeSH data available.


Related in: MedlinePlus

Patterns of connectivity of the VMH region in MA exposed (A) and MA naïve (B) mice. The thickness and color of the edges (red for positive and blue for negative) corresponds to the strength and direction (positive or negative) of the correlations. VMH displays changes in correlations with a number of other regions; the combined effects of these changes is quantified as change in connectivity.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4585047&req=5

Figure 7: Patterns of connectivity of the VMH region in MA exposed (A) and MA naïve (B) mice. The thickness and color of the edges (red for positive and blue for negative) corresponds to the strength and direction (positive or negative) of the correlations. VMH displays changes in correlations with a number of other regions; the combined effects of these changes is quantified as change in connectivity.

Mentions: Next, we directly tested the hypothesis that VMH connectivity is significantly altered following exposure to MA. As detailed in Methods, we employed a bootstrapping procedure which involved combining the MA and saline data, randomly assigning each sample to one of two mixed groups (N = 10, 000), and computing the differences between these groups. Differences between groups arranged in this manner are expected to be small and to reflect spurious changes arising from pure chance. Compared with this distribution of random differences, the difference in VMH connectivity between the MA exposed and saline exposed networks corresponds to a Z-score of 2.6 and a bootstrap p-value. We illustrate these results in Figure 7.


Enhanced functional connectivity involving the ventromedial hypothalamus following methamphetamine exposure.

Zuloaga DG, Iancu OD, Weber S, Etzel D, Marzulla T, Stewart B, Allen CN, Raber J - Front Neurosci (2015)

Patterns of connectivity of the VMH region in MA exposed (A) and MA naïve (B) mice. The thickness and color of the edges (red for positive and blue for negative) corresponds to the strength and direction (positive or negative) of the correlations. VMH displays changes in correlations with a number of other regions; the combined effects of these changes is quantified as change in connectivity.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4585047&req=5

Figure 7: Patterns of connectivity of the VMH region in MA exposed (A) and MA naïve (B) mice. The thickness and color of the edges (red for positive and blue for negative) corresponds to the strength and direction (positive or negative) of the correlations. VMH displays changes in correlations with a number of other regions; the combined effects of these changes is quantified as change in connectivity.
Mentions: Next, we directly tested the hypothesis that VMH connectivity is significantly altered following exposure to MA. As detailed in Methods, we employed a bootstrapping procedure which involved combining the MA and saline data, randomly assigning each sample to one of two mixed groups (N = 10, 000), and computing the differences between these groups. Differences between groups arranged in this manner are expected to be small and to reflect spurious changes arising from pure chance. Compared with this distribution of random differences, the difference in VMH connectivity between the MA exposed and saline exposed networks corresponds to a Z-score of 2.6 and a bootstrap p-value. We illustrate these results in Figure 7.

Bottom Line: MA phase shifts, entrains the circadian clock and can also alter the entraining effect of light by currently unknown mechanisms.There were five distinct patterns of neuronal activation.Functional connectivity between the ventromedial hypothalamus (VMH) and other brain areas, including the paraventricular nucleus of the hypothalamus and basolateral and medial amygdala, was enhanced following MA exposure, suggesting a role for the VMH in the effects of MA on the brain.

View Article: PubMed Central - PubMed

Affiliation: Department of Behavioral Neuroscience, Oregon Health & Science University Portland Portland, OR, USA ; Department of Psychology, University at Albany Albany, NY, USA.

ABSTRACT
Methamphetamine (MA) consumption causes disruption of many biological rhythms including the sleep-wake cycle. This circadian effect is seen shortly following MA exposure and later in life following developmental MA exposure. MA phase shifts, entrains the circadian clock and can also alter the entraining effect of light by currently unknown mechanisms. We analyzed and compared immunoreactivity of the immediate early gene c-Fos, a marker of neuronal activity, to assess neuronal activation 2 h following MA exposure in the light and dark phases. We used network analyses of correlation patterns derived from global brain immunoreactivity patterns of c-Fos, to infer functional connectivity between brain regions. There were five distinct patterns of neuronal activation. In several brain areas, neuronal activation following exposure to MA was stronger in the light than the dark phase, highlighting the importance of considering circadian periods of increased effects of MA in defining experimental conditions and understanding the mechanisms underlying detrimental effects of MA exposure to brain function. Functional connectivity between the ventromedial hypothalamus (VMH) and other brain areas, including the paraventricular nucleus of the hypothalamus and basolateral and medial amygdala, was enhanced following MA exposure, suggesting a role for the VMH in the effects of MA on the brain.

No MeSH data available.


Related in: MedlinePlus