OBJECTIVE: To observe the effects of moxa smoke through olfactory pathway on learning and memory ability in rapid aging (SAMP8) mice, and to explore the action pathway of moxa smoke. METHODS: Forty-eight six-month-old male SAMP8 mice were randomly divided into a model group, an olfactory dysfunction group, a moxa smoke group and an olfactory dysfunction + moxa smoke group, with 12 mice in each group. Twelve age-matched male SAMR1 mice were used as the blank group. The olfactory dysfunction model was induced in the olfactory dysfunction group and the olfactory dysfunction + moxa smoke group by intraperitoneal injection of 3-methylindole (3-MI) with 300 mg/kg, and the moxa smoke group and the olfactory dysfunction + moxa smoke group were intervened with moxa smoke at a concentration of 10-15 mg/m³ for 30 min per day, with a total of 6 interventions per week. After 6 weeks, the emotion and cognitive function of mice was tested by open field test and Morris water maze test, and the neuronal morphology in the CAI area of the hippocampus was observed by HE staining. The contents of neurotransmitters (glutamic acid [Glu], gamma-aminobutyric acid [GABA], dopamine [DA], and 5-hydroxytryptamine [5-HT]) in hippocampal tissue of mice were detected by ELISA. RESULTS: The mice in the blank group, the model group and the moxa smoke group could find the buried food pellets within 300 s, while the mice in the olfactory dysfunction group and the olfactory dysfunction + moxa smoke group took more than 300 s to find them. Compared with the blank group, the model group had increased vertical and horizontal movements (P<0.05) and reduced central area residence time (P<0.05) in the open field test, prolonged mean escape latency on days 1-4 (P<0.05), and decreased search time, swimming distance and swimming distance ratio in the target quadrant of the Morris water maze test, and decreased GABA, DA and 5-HT contents (P<0.05, P<0.01) and increased Glu content (P<0.05) in hippocampal tissue. Compared with the model group, the olfactory dysfunction group had increased vertical movements (P<0.05), reduced central area residence time (P<0.05), and increased DA content in hippocampal tissue (P<0.05); the olfactory dysfunction + moxa smoke group had shortened mean escape latency on days 3 and 4 of the Morris water maze test (P<0.05) and increased DA content in hippocampal tissue (P<0.05); the moxa smoke group had prolonged search time in the target quadrant (P<0.05) and increased swimming distance ratio, and increased DA and 5-HT contents in hippocampal tissue (P<0.05, P<0.01) and decreased Glu content in hippocampal tissue (P<0.05). Compared with the olfactory dysfunction group, the olfactory dysfunction + moxa smoke group showed a shortened mean escape latency on day 4 of the Morris water maze test (P<0.05). Compared with the moxa smoke group, the olfactory dysfunction + moxa smoke group had a decreased 5-HT content in the hippocampus (P<0.05). Compared with the blank group, the model group showed a reduced number of neurons in the CA1 area of the hippocampus with a disordered arrangement; the olfactory dysfunction group had similar neuronal morphology in the CA1 area of the hippocampus to the model group. Compared with the model group, the moxa smoke group had an increased number of neurons in the CA1 area of the hippocampus that were more densely packed. Compared with the moxa smoke group, the olfactory dysfunction + moxa smoke group had a reduced number of neurons in the CA1 area of the hippocampus, with the extent between that of the moxa smoke group and the olfactory dysfunction group. CONCLUSION The moxa smoke could regulate the contents of neurotransmitters Glu, DA and 5-HT in hippocampal tissue through olfactory pathway to improve the learning and memory ability of SAMP8 mice, and the olfactory is not the only effective pathway.
Male ; Animals ; Mice ; Olfactory Pathways ; Smoke/adverse effects* ; Serotonin ; Aging ; Dopamine ; Olfaction Disorders/etiology*

This study aims to explore the auditory response characteristics of the thalamic reticular nucleus (TRN) in awake mice during auditory information processing, so as to deepen the understanding of TRN and explore its role in the auditory system. By in vivo electrophysiological single cell attached recording of TRN neurons in 18 SPF C57BL/6J mice, we observed the responses of 314 recorded neurons to two kinds of auditory stimuli, noise and tone, applied to mice. The results showed that TRN received projections from layer six of the primary auditory cortex (A1). Among 314 TRN neurons, 56.05% responded silently, 21.02% responded only to noise and 22.93% responded to both noise and tone. The neurons with noise response can be divided into three patterns according to their response time: onset, sustain and long-lasting, accounting for 73.19%, 14.49% and 12.32%, respectively. The response threshold of the sustain pattern neurons was lower than those of the other two types. Under noise stimulation, compared with A1 layer six, TRN neurons showed unstable auditory response (P < 0.001), higher spontaneous firing rate (P < 0.001), and longer response latency (P < 0.001). Under tone stimulation, TRN's response continuity was poor, and the frequency tuning was greatly different from that of A1 layer six (P < 0.001), but their sensitivity to tone was similar (P > 0.05), and TRN's tone response threshold was much higher than that of A1 layer six (P < 0.001). The above results demonstrate that TRN mainly undertakes the task of information transmission in the auditory system. The noise response of TRN is more extensive than the tone response. Generally, TRN prefers high-intensity acoustic stimulation.
Rats ; Mice ; Animals ; Wakefulness ; Auditory Pathways/physiology* ; Rats, Wistar ; Mice, Inbred C57BL ; Thalamus/physiology*

Pain is a multi-dimensional emotional experience, and pain sensation and pain emotion are the two main components. As for pain, previous studies only focused on a certain link of the pain transmission pathway or a certain key brain region, and there is a lack of evidence that connectivity of brain regions is involved in pain or pain regulation in the overall state. The establishment of new experimental tools and techniques has brought light to the study of neural pathways of pain sensation and pain emotion. In this paper, the structure and functional basis of the neural pathways involved in the formation of pain sensation and the regulation of pain emotion in the nervous system above the spinal cord level, including thalamus, amygdala, midbrain periaqueductal gray (PAG), parabrachial nucleus (PB) and medial prefrontal cortex (mPFC), are reviewed in recent years, providing clues for the in-depth study of pain.
Humans ; Pain ; Neural Pathways/physiology* ; Periaqueductal Gray/physiology* ; Brain ; Spinal Cord/physiology* ; Magnetic Resonance Imaging

Humans ; Auditory Pathways ; Hearing Loss, Sensorineural ; Cochlear Implantation ; Cochlear Implants ; Hearing Loss, Central ; Auditory Threshold ; Evoked Potentials, Auditory, Brain Stem

Zona Incerta ; Prefrontal Cortex ; Fear ; Neural Pathways

OBJECTIVES: To observe the effects of zhongfeng cutong moxibustion (moxibustion therapy for unblocking and treating stroke) on the motor function and the structure of corticospinal tract (CST) in the patients with motor dysfunction during the recovery period of cerebral infarction, and to explore the central mechanism of this moxibustion therapy for improving the motor function. METHODS: Fifty patients with motor dysfunction during the recovery period of cerebral infarction were randomly divided into an observation group (25 cases, 1 case dropped out) and a control group (25 cases, 1 case dropped out). The patients in both groups underwent the conventional basic treatment. In the control group, acupuncture was applied to Baihui (GV 20) and Shuigou (GV 26), as well as Chize (LU 5), Neiguan (PC 6), Weizhong (BL 40) and Sanyinjiao (SP 6) etc. on the affected side. Besides the intervention of the control group, in the observation group, zhongfeng cutong moxibustion therapy was combined at Baihui (GV 20), Shenque (CV 8) and bilateral Zusanli (ST 36). Both acupuncture and moxibustion therapies were delivered once daily, 5 times a week, for 2 weeks. The scores of Fugl-Meyer assessment scale (FMA) and National Institutes of Health stroke scale (NIHSS) were compared between the two groups before and after treatment. The diffusion tensor imaging technique was used to observe the fractional anisotropy (FA) of CST at the bilateral whole segment, the cerebral cortex, the posterior limb of the internal capsule and the cerebral peduncle before and after treatment in the two groups. RESULTS: The scores of the upper and the lower limbs of FMA, as well as the total FMA score swere increased after treatment when compared with those before treatment in the two groups (P<0.05), the upper limb FMA score and the total FMA score in the observation group were higher than those in the control group (P<0.05), and NIHSS scores of the two groups were dropped compared with those before treatment (P<0.01). FA of CST at the bilateral sides of the posterior limb of the internal capsule and the whole segment on the focal side was improved in comparison with that before treatment in the observation group (P<0.05), and FA of CST at the healthy side of the whole segment was higher than that before treatment in the control group (P<0.05). CONCLUSIONS Zhongfeng cutong moxibustion improves motor function and reduces neurological deficits in the patients with motor dysfunction during the recovery period of cerebral infarction, which may be related to enhancing the remodeling of white matter fiber bundles in the corticospinal tract on the focal side of the whole segment and the bilateral posterior limb of the internal capsule.
Humans ; Moxibustion ; Pyramidal Tracts ; Diffusion Tensor Imaging ; Acupuncture Therapy ; Cerebral Infarction/therapy* ; Stroke/therapy* ; Acupuncture Points ; Treatment Outcome

Basolateral Nuclear Complex ; Amygdala ; Neural Pathways

Gyrus Cinguli ; Claustrum ; Cerebral Cortex ; Basal Ganglia ; Motor Activity ; Neural Pathways

OBJECTIVES: To investigate the characteristics and objective assessment method of visual field defects caused by optic chiasm and its posterior visual pathway injury. METHODS: Typical cases of visual field defects caused by injuries to the optic chiasm, optic tracts, optic radiations, and visual cortex were selected. Visual field examinations, visual evoked potential (VEP) and multifocal visual evolved potential (mfVEP) measurements, craniocerebral CT/MRI, and retinal optical coherence tomography (OCT) were performed, respectively, and the aforementioned visual electrophysiological and neuroimaging indicators were analyzed comprehensively. RESULTS: The electrophysiological manifestations of visual field defects caused by optic chiasm injuries were bitemporal hemianopsia mfVEP abnormalities. The visual field defects caused by optic tract, optic radiation, and visual cortex injuries were all manifested homonymous hemianopsia mfVEP abnormalities contralateral to the lesion. Mild relative afferent pupil disorder (RAPD) and characteristic optic nerve atrophy were observed in hemianopsia patients with optic tract injuries, but not in patients with optic radiation or visual cortex injuries. Neuroimaging could provide morphological evidence of damages to the optic chiasm and its posterior visual pathway. CONCLUSIONS Visual field defects caused by optic chiasm, optic tract, optic radiation, and visual cortex injuries have their respective characteristics. The combined application of mfVEP and static visual field measurements, in combination with neuroimaging, can maximize the assessment of the location and degree of visual pathway damage, providing an effective scheme for the identification of such injuries.
Humans ; Optic Chiasm/pathology* ; Visual Pathways/pathology* ; Visual Fields ; Evoked Potentials, Visual ; Random Amplified Polymorphic DNA Technique ; Hemianopsia/complications* ; Vision Disorders/pathology* ; Optic Nerve Injuries/diagnostic imaging* ; Brain Injuries, Traumatic/diagnostic imaging*

Neurons are highly interwoven to form intricate neural circuits that underlie the diverse functions of the brain. Dissecting the anatomical organization of neural circuits is key to deciphering how the brain processes information, produces thoughts, and instructs behaviors. Over the past decades, recombinant viral vectors have become the most commonly used tracing tools to define circuit architecture. In this review, we introduce the current categories of viral tools and their proper application in circuit tracing. We further discuss some advances in viral tracing strategy and prospective innovations of viral tools for future study.
Synapses/physiology* ; Prospective Studies ; Neurons/physiology* ; Genetic Vectors ; Brain/physiology* ; Neural Pathways/physiology*