Connectivity Study of the Neuromechanism of Acute Acupuncture Needling during fMRI in "Overweight" Subjects

Abstract

This functional connectivity study depicts how acupoints ST 36 and SP 9 and their sham acupoints acutely act on blood glucose (GLU), core body temperature (CBT), hunger, and sensations pertaining to needling (De-qi) via the limbic system and dopamine (DA) to affect various brain areas in fasting, adult, and "overweight" Chinese males using functional magnetic resonance imaging. Functional connectivity (FC) analysis utilized the amygdala (AMY) and hypothalamus (HYP) as regions of interest (ROIs) in the discrete cosine transform and seed correlation analysis methods. There was a significant difference in the spatial patterns of the distinct brain regions between groups. Correlation results showed that increased HYP-hippocampus FC after ACU was positively correlated with ACU-induced change in CBT; increased HYP-putamen-insula FC after ACU was positively correlated with ACU-induced change in GLU; and increased HYP-anterior cingulate cortex FC after ACU was positively correlated with ACU-induced change in HUNGER suggesting that increased DA modulation during ACU was probably associated with increased poststimulation limbic system and spinothalamic tract connectivity. Decreased HYP-thalamus FC after ACU was negatively correlated or anticorrelated with ACU-induced change in HUNGER suggesting that increased DA modulation during ACU was possibly associated with decreased poststimulation limbic system and spinothalamic tract connectivity. No correlation was found for min SHAM. This was an important study in addressing acute acupuncture effects and neural pathways involving physiology and appetite regulation in overweight individuals.

Figure 1

Description of functional magnetic resonance imaging experimental design for acupuncture done on right-handed, overweight Chinese males (age 21–45 years). Diagram shows the location of the two acupoints, ST 36 and SP 9, used for the acupuncture experiment. Experiment  1 Session I delineates the progression of the experimental procedures for n = 10 patients. Experiment  2 Session II for the minimal Sham procedure (n = 9) is described verbally in the note. Abbreviations: CBT: core body temperature; GLU: glucose; BMI: body mass index; PE: physical examination; http://bhojraj.tripod.com/July03knee.gif.

Figure 2

Blood oxygen level-dependent (BOLD) signals in significant brain regions from a hypothalamus-related functional connectivity analysis comparing real acupuncture (ACU) versus minimal sham- (min SHAM-) treated individuals (n = 10 and n = 9, resp.). Epoch of treatment lasted 9 min. Results from the conjunction analysis were based on the discrete cosine transform (DCT) group results for acupoints ST 36 and SP 9. The overlapping areas are the putamen, insula, parahippocampus, hippocampus, amygdala, anterior cingulate cortex (ACC), thalamus, and pons. T-value scales are located on the bottom of the picture (P < 0.05).

Figure 3

Blood oxygen level-dependent (BOLD) signals in significant brain regions from an amygdala-related functional connectivity analysis comparing real acupuncture (ACU) versus minimal sham- (min SHAM-) treated individuals (n = 10 and n = 9, resp.). Epoch of treatment lasted 9 min. Results from the conjunction analysis were based on the discrete cosine transform (DCT) group results for acupoints ST 36 and SP 9. The overlapping areas are the putamen, insula, parahippocampus, hippocampus, hypothalamus, and cerebellum. T-value scales are located on the bottom of the picture (P < 0.05).

Figure 4

Changes in functional connectivity (FC) with the hippocampus (HIPP) after acupunture minus before acupuncture (ACU) in relation to delta temperature correlation scores after ACU minus before ACU. Increased hypothalamus-hippocampus functional connectivity (HYP–HIPP FC) after acupuncture (after ACU) was positively correlated with ACU-induced change in core body temperature suggesting that increased dopamine modulation during ACU was possibly associated with increased poststimulation limbic system and spinothalamic tract connectivity (r = 0.66; P = 0.03).

Figure 5

Changes in functional connectivity (FC) with the putamen (PUT) after acupuncture minus before acupuncture (ACU) in relation to delta glucose (GLU) correlation scores after ACU minus before ACU. Increased hypothalamus-putamen (L = left; R = right) functional connectivity (HYP-PUT FC) after acupuncture (after ACU) was positively correlated with ACU-induced change in GLU suggesting that increased dopamine modulation during ACU was probably associated with increased poststimulation limbic system and spinothalamic tract connectivity (left putamen r = 0.82, P = 0.00; right putamen r = 0.79, P = 0.01).

Figure 6

Changes in functional connectivity (FC) with the insula after acupuncture minus before acupuncture (ACU) in relation to delta glucose (GLU) correlation scores after ACU minus before ACU. Increased hypothalamus-insula functional connectivity (HYP-INS FC) after acupuncture (after ACU) was positively correlated with ACU-induced change in GLU suggesting that increased dopamine modulation during ACU was deemed to be associated with increased poststimulation limbic system and spinothalamic tract connectivity (r = 0.66; P = 0.03).

Figure 7

Changes in functional connectivity (FC) with the anterior cingulate cortex (ACC) after acupuncture minus before acupuncture (ACU) in relation to delta hunger correlation scores after ACU minus before ACU. Increased hypothalamus-ACC functional connectivity (HYP-ACC FC) after acupuncture (after ACU) was positively correlated with ACU-induced change in hunger suggesting that increased dopamine modulation during ACU was presumably associated with increased poststimulation limbic system and spinothalamic tract connectivity (r = 0.60; P = 0.05).

Figure 8

Changes in functional connectivity (FC) with the thalamus after minus before acupuncture (ACU) in relation to delta hunger correlation scores after ACU minus before ACU. Decreased hypothalamus-thalamus (L: left; R: right) functional connectivity (HYP-THALAMUS FC) after acupuncture (after ACU) was negatively correlated with ACU-induced change in hunger suggesting that increased dopamine modulation during ACU was most likely associated with decreased poststimulation limbic system and spinothalamic tract connectivity (left thalamus r = −0.64, P = 0.05; right thalamus r = −0.58, P = 0.08).