Free-Ranging Macaque Mothers Exaggerate Tool-Using Behavior when Observed by Offspring

Abstract

Background: Neonatal colon irritation (CI; pain or inflammation) given for 2 weeks prior to postnatal day 22 (PND22), causes long-lasting functional disorders in rats that can be seen 6 months after the initial insult. This study looked at the effect of varying the frequency and duration of neonatal CI on the rate of growth, digestive outcomes, exploratory activity, and colon and skin sensitivity in adult rats.

Role of sympathetic nervous system in rat model of chronic visceral pain

“…We have now demonstrated SNS‐driven hyperalgesia in a chronic pain model. The chronic CI model was selected because it is induced without direct nerve injury and the visceral hypersensitivity persists for many months after it is induced . The rats have altered water content in their fecal output, a marker consistent with symptoms of constipation or diarrhea seen in patients with IBS.…”

“…No treatment, procedure, or further intervention was done by the investigator until the rats were adult. The CI rats used in this study were hypersensitive to CRD and selected with no signs of altered fecal output (for additional details on animal preparation, see Wang et al …”

“…Using a rat colon irritation (CI) model of chronic visceral hypersensitivity with hallmarks of IBS including visceral and somatic hypersensitivity and altered stool function, we investigated whether sympathoneuronal outflow can drive the chronic pain state. In this model, rats that are treated to a series of colonic balloon distensions as neonates develop visceral hypersensitivity to the colonic balloon distension that persists into adulthood . This hypersensitivity is coupled with a change in descending modulation from being predominantly inhibitory to predominantly facilitatory …”

The consequences of pain in early life: injury‐induced plasticity in developing pain pathways

“…Many have been adapted from adult pain research and compare similar types and severities of injury in neonatal and adult rodents. These include: neonatal hindpaw plantar incision (Walker et al ., ), hindpaw inflammation with agents such as carrageenan (CAR) or complete Freund's adjuvant (CFA) (Beland & Fitzgerald, ; Walker et al ., ; Ren et al ., ; Hohmann et al ., ; LaPrairie & Murphy, ), full thickness skin wound (Reynolds & Fitzgerald, ; Beggs et al ., ), repeated needle prick (Anand et al ., ; Knaepen et al ., ), peripheral nerve injury (Howard et al ., ; Vega‐Avelaira et al ., ) and visceral injury caused by distension or inflammation (Al‐Chaer et al ., ; Randich et al ., ; Wang et al ., ).…”

Down‐regulation of A‐type potassium channel in gastric‐specific DRG neurons in a rat model of functional dyspepsia

“…Further research using immunofluoresence stain to examine the expressions of subfamilies of K V channels in DiI‐labeled gastric‐specific DRG neurons is warranted to study the detailed molecular mechanism underlying the gastric hypersensitivity in the rodent model of FD. Neonatal colon irritation with colorectal distension was reported to cause long‐lasting visceral hypersensitivity along with increased somatic sensitivity in adult rats compared to control rats handled by the investigator without any intracolonic insertion, indicating global plastic changes affecting more than one system . Activation of hypothalamic–pituitary–adrenal axis is a common factor for psychological and inflammatory stressors and plays an important role in down‐regulating mRNA of K V 1.1 in gastric‐specific DRG neuron in adult rats with neonatal colon irritation .…”