Abstract：
Wide-range thermoreceptive neurons (WRT-EN) in monkey cortical area 7b that encoded innocuous and nocuous cutaneous thermal and threatening visuosensory stimulation with high fidelity were studied to identify their multisensory integrative response properties. Emphasis was given to characterizing the spatial and temporal effects of threatening visuosensory input on the thermal stimulus-response properties of these multisensory nociceptive neurons. Threatening visuosensory stimulation was most efficacious in modulating thermal evoked responses when presented as a downward (\"looming\"), spatially congruent, approaching and closely proximal target in relation to the somatosensory receptive field. Both temporal alignment and misalignment of spatially aligned threatening visual and thermal stimulation significantly increased mean discharge frequencies above those evoked by thermal stimulation alone, particularly at near noxious (43°C) and mildly noxious (45°C) temperatures. The enhanced multisensory discharge frequencies were equivalent to the discharge frequency evoked by overtly noxious thermal stimulation alone at 47°C (monkey pain tolerance threshold). A significant increase in behavioral mean escape frequency with shorter escape latency was evoked by multisensory stimulation at near noxious temperature (43°C), which was equivalent to that evoked by noxious stimulation alone (47°C). The remarkable concordance of elevating both neural discharge and escape frequency from a nonnociceptive and prepain level by near noxious thermal stimulation to a nociceptive and pain level by multisensory visual and near noxious thermal stimulation and integration is an elegantly designed defensive neural mechanism that in effect lowers both nociceptive response and pain thresholds to preemptively engage nocifensive behavior and, consequently, avert impending and actual injurious noxious thermal stimulation.NEW & NOTEWORTHY Multisensory nociceptive neurons in cortical area 7b are engaged in integration of threatening visuosensory and a wide range of innocuous and nocuous somatosensory (thermoreceptive) inputs. The enhancement of neuronal activity and escape behavior in monkey by multisensory integration is consistent and supportive of human psychophysical studies. The spatial features of visuosensory stimulation in peripersonal space in relation to somatic stimulation in personal space are critical to multisensory integration, nociception, nocifensive behavior, and pain.
摘要：
研究了猴子皮质区域7b中的宽范围热感受神经元（WRT-EN），它们以高保真度编码了无害和无害的皮肤热和威胁性的视觉感觉刺激，以鉴定其多感觉整合反应特性。重点是表征威胁性视觉感觉输入对这些多感觉伤害性神经元的热刺激响应特性的时空影响。威胁性视觉感觉刺激在调节热诱发反应时表现为向下（“隐现”）时最有效，空间一致，与体感感受野相关的接近和接近目标。空间对准的威胁视觉和热刺激的时间对准和未对准均显着增加了平均放电频率，高于仅由热刺激引起的频率，特别是在接近有害（43°C）和轻度有害（45°C）的温度下。增强的多感官放电频率相当于仅在47°C（猴子疼痛耐受阈值）时由明显有害的热刺激引起的放电频率。在接近有害温度（43°C）的情况下，多感官刺激引起的行为平均逃避频率显着增加，逃避潜伏期较短，这相当于仅由有害刺激引起的（47°C）。通过近伤害性热刺激将神经放电和逃避频率从非伤害性和疼痛前水平提高到通过多感官视觉和近伤害性热刺激和整合的伤害性和疼痛水平的显着一致性是一种优雅设计的防御性神经机制，实际上降低了伤害性反应和疼痛阈值，从而先发制人地进行不良行为，避免即将发生和实际有害的有害热刺激。
