Table 1 Overview of preclinical and clinical studies on the involvement of the Hypothalamus in the TNP processing pathway
Subject condition | Stimulation method | Analyzing procedure | Analyzed brain region | Findings of hypothalamus | Reference |
|---|---|---|---|---|---|
Formalin- induced orofacial pain in rats | Intra-LH microinjection of Carbachol, formalin injection into the upper lip | Histological verification | LH | Neural activation | [165] |
Nociceptive dural input in rats | Hypothalamic microinjections of Orexin A and B | Extracellular recordings | PH | Increased activity | [9] |
TNP in mice | CCI-ION | Behavioral tests, optogenetic and chemogenetic manipulation, IHC | Hypothalamic A11 nucleus | Increased activity | [114] |
Trigeminal pain processing in rats | Microinjections of Fluorogold (FG) into TNC | IHC | PVN, LH, A11. | Increased activity | [1] |
Trigeminal pain processing in rats | Facial formalin test, microinjections of Muscimol and 6-OHDA | Behavioral tests, IHC, Fos expression | Hypothalamic A11 nucleus | Increased activity in GABAergic neurons. | [2] |
Nociceptive dural input in rats | Microinjections (Bicuculline, Somatostatin, Cyclo-somatostatin) into PH | Extracellular recordings | PH | Increased activity in GABAergic neurons. | [10] |
Light-evoked trigeminal neural activity in rats | Bright light stimulation, microinjections of BMI into PH | Electrophysiological recordings, reflex lacrimation, MAP | PH | Increased activity | [94] |
TNP in rats | CCI-ION | In vivo extracellular recordings, behavioral tests, IFC | PH | Increased PH activity in response to trigeminal pain​. | [82] |
Orofacial pain in rats | Capsaicin injection | Behavior tests, microinjections and pharmacological manipulations, histological analysis | PH | Increased orexinergic activity | [101] |
TNP | DBS | Neuroimaging (PET, fMRI), clinical assessments, electrophysiology | PH | Increased activity in the PH | [153] |
Trigeminal autonomic reflex in healthy participants | Kinetic oscillation stimulation | fMRI | AH | Increased activity | [134] |
Orofacial pain in rats | Chemical stimulation using carbachol | Behavior tests, histological analysis | LH | Neural activation | [63] |
TNP | CCI-ION | Behavior tests, microinjections and pharmacological manipulations, histological analysis | Posterolateral hypothalamus | Loss of noradrenergic terminals | [95] |
Orofacial pain in rats | Capsaicin injection | Behavior tests, histological analysis | PH | Increased orexinergic activity | [102] |
TNP  trigeminal neuropathic pain, fMRI functional magnetic resonance imaging, DBS deep brain stimulation, LH lateral hypothalamus, PET positron emission tomography, PH posterior hypothalamus, PVN paraventricular nucleus, AH anterior hypothalamus, CCI-ION chronic constriction injury of infraorbital nerve | |||||