Targeting Topics 09q2

Noradrenergic Neurons in the Locus Coeruleus Contribute to Neuropathic Pain

Brightwell JJ, Taylor BK

Neuroscience 160(1):174-185, 2009.

Noradrenergic neurons were eliminated with 5 µg intracerebroventricular injections of anti-DBH-SAP (Cat. #IT-03). Mouse IgG-SAP (Cat. #IT-18) was used as a control. Animals lesioned with anti-DBH-SAP displayed a reduction in behavioral signs of several kinds of allodynia.

Neuropeptide Y receptor-expressing dorsal horn neurons: Role in nocifensive reflex responses to heat and formalin

Wiley RG, Lemons LL, Kline RH

Neuroscience 161(1):139-147, 2008.

This work examines the effect of lumbar intrathecal administration of NPY-SAP (Cat. #IT-28), and the role of Y1 NPY receptor-expressing neurons (Y1R) in response to thermal and chemical stimulation. Rats received 500 ng or 750 ng intrathecal injections of NPY-SAP. Blank-SAP (Cat. #IT-21) was used as a control. Lesioned animals displayed a specific loss of Y1R in the dorsal horn, as well as reduced nocifensive reflex responses.

Cognitive Performances of Cholinergically Depleted Rats Following Chronic Donepezil Administration

Cutuli D, Foti F, Mandolesi L, De Bartolo P, Gelfo F, Federico F, Petrosini L

J Alzheimers Dis 17(1):161-176, 2009.

The authors examined whether donepezil could improve cognitive functions in rats with lesions of the cholinergic cells in the forebrain. Treated animals received 4 µg bilateral intracerebroventricular injections of 192-IgG-SAP (Cat. #IT-01), followed by treatment with donepezil or a control. Donepezil-treated animals performed significantly better than control animals.

Spinal NK-1 receptor-expressing neurons and descending pathways support fentanyl-induced pain hypersensitivity in a rat model of postoperative pain

Rivat C, Vera-Portocarrero LP, Ibrahim MM, Mata HP, Stagg NJ, De Felice M, Porreca F, Malan TP

Eur J Neurosci 29(4):727-737, 2009.

Opioids activate hyperalgesia and allodynia. The authors test the hypothesis that NK-1 receptor-containing ascending pathways play a role in sensitivity to fentanyl. Rats received an intrathecal injection of SP-SAP (Cat. #IT-07), and controls received saporin (Cat. #PR-01). The data indicate that these ascending pathways have a role in fentanyl-induced hyperalgesia.

Dependence of monocyte chemoattractant protein 1 induced hyperalgesia on the isolectin B4-binding protein versican

Bogen O, Dina OA, Gear RW, Levine JD

Neuroscience 159(2):780-786, 2009.

Monocyte chemoattractant protein 1 (MCP-1) is involved in generation of inflammatory and neuropathic pain, but the mechanisms underlying this involvement are not understood. Rats received 3.2 µg intrathecal injections of IB4-SAP (Cat. #IT-10). Ten days later the rats received intradermal MCP-1. Animals treated with IB4-SAP did not exhibit the mechanical hyperalgesia normally seen when treated with MCP-1.

Efficacy of a murine-p75-saporin immunotoxin for selective lesions of basal forebrain cholinergic neurons in mice

Nag N, Baxter MG, Berger-Sweeney JE

Neurosci Lett 452(3):247-251, 2009.

The authors tested a new version of mu p75-SAP (Cat. #IT-16) in mice. Mice received bilateral injections of 0.65 or 1.3 µg of immunotoxin into each lateral ventricle. Both amounts produced a complete loss of cholinergic neurons in the medial septum, while a dose-dependent loss of cholinergic neurons was seen in the nucleus basalis magnocellularis.

Developmental forebrain cholinergic lesion and environmental enrichment: behaviour, CA1 cytoarchitecture and neurogenesis

Frechette M, Rennie K, Pappas BA

Brain Res 1252:172-182, 2009.

The authors investigated the effect of neonatal cholinergic lesions on plasticity in the presence or absence of enrichment. Each lateral ventricle of 7 day-old rats received 300 ng of 192-IgG-SAP (Cat. #IT-01). Although the lesions did not attenuate neurobehavioral plasticity, there were several physiological changes that occurred despite the environmental enrichment.

Segregated populations of hippocampal principal CA1 neurons mediating conditioning and extinction of contextual fear

Tronson NC, Schrick C, Guzman YF, Huh KH, Srivastava DP, Penzes P, Guedea AL, Gao C, Radulovic J

J Neurosci 29(11):3387-3394, 2009.

This work examines what cell groups are responsible for controlling contextual fear. 180 ng of mu p75-SAP (Cat. #IT-16) was injected into the medial septum of mice. Saporin (Cat. #PR-01) was used as a control. In lesioned animals, fear extinction was lost along with the cholinergic input from the medial septum, while fear conditioning was left intact.

Cardiac damage after lesions of the nucleus tractus solitarii

Nayate A, Moore SA, Weiss R, Taktakishvili OM, Lin LH, Talman WT

Am J Physiol Regul Integr Comp Physiol 296(2):R272-279, 2009.

This work tested the hypothesis that nucleus tractus solitarii (NTS) lesions can lead to fatal cardiac arrhythmias and myocardial lesions. Rats received bilateral injections of 9.4 ng of SSP-SAP (Cat. #IT-11) into the dorsolateral and medial portions of the NTS. Lesioned animals displayed increased arterial blood pressure.

Neuroprotective effects of testosterone on the morphology and function of somatic motoneurons following the death of neighboring motoneurons

Little CM, Coons KD, Sengelaub DR

J Comp Neurol 512(3):359-372, 2009.

Atrophy of androgen-sensitive motoneurons due to proximity to damaged motoneurons can be attenuated by testosterone. This work examined whether typical motoneurons respond in the same way. Rats received 5-ng injections of CTB-SAP (Cat. #IT-14) that eliminated motoneurons innervating the vastus medialis muscle. Partial motoneuron depletion resulted in atrophy of the remaining quadriceps motoneurons; this was attenuated by the administration of testosterone.

Noradrenergic, but not cholinergic, deafferentation of prefrontal cortex impairs attentional set-shifting

McGaughy J, Ross RS, Eichenbaum H

Neuroscience 153(1):63-71, 2008.

Norepinephrine and acetylcholine are involved in the mediation of attention, however, it is not yet clear whether the roles of these molecules are unique. This work utilizes a specific task shown to dissociate the roles played by the dorsolateral prefrontal cortex and the orbitofrontal cortex in primates. Rats received 5-ng infusions of anti-DBH-SAP (Cat. #IT-03) or 192-IgG-SAP (Cat. #IT-01) into each hemisphere. The type of lesion had an effect on attentional shifts and reaction to irrelevant stimuli.

Sex differences in micro-opioid receptor expression in the rat midbrain periaqueductal gray are essential for eliciting sex differences in morphine analgesia

Loyd DR, Wang X, Murphy AZ

J Neurosci 28(52):14007-14017, 2008.

The authors test whether the periaqueductal gray (PAG), that contains a dense population of µ-opioid receptor (MOR)-expressing neurons, is sexually dimorphic. Rats were injected with 3 pmol of Dermorphin-SAP (Cat. #IT-12) into the PAG. Blank-SAP (Cat. #IT-21) was used as a control. Both behavioral and immunohistochemical evidence suggest that differential expression of MOR-expressing neurons in the PAG between male and female rats accounts for the difference in response to morphine.

Anxiety-like behavior is modulated by a discrete subpopulation of interneurons in the basolateral amygdala

Truitt WA, Johnson PL, Dietrich AD, Fitz SD, Shekhar A

Neuroscience 160(2):284-294, 2009.

It is thought that the basolateral nucleus of the amygdala (BL) is an anxiety regulator. The authors previously demonstrated that SSP-SAP (Cat. #IT-11) lesions of the BL increase anxiety-like behaviors in rats. Using a series of 6 bilateral injections of SSP-SAP (4 ng per injection), the NK-1 receptor-expressing cells of the BL are further characterized.

Neural regulation of ejaculation

Young B, Coolen L, McKenna K

J Sex Med 6 Suppl 3:229-233, 2009.

This review summarizes that a specific population of lumbar spinothalamic (LSt) cells plays in regulation of the ejaculatory response. One method to study these cells is the injection of SSP-SAP (Cat. #IT-11) into the LSt cells surrounding the central canal. Over 90% of these cells express the NK-1 receptor. This lesion significantly disrupts ejaculation without affecting mounts or intromissions.

Targeted ablation of cardiac sympathetic neurons reduces resting, reflex, and exercise-induced sympathetic activation in conscious rats

Lujan HL, Palani G, Chen Y, Peduzzi-Nelson J, DiCarlo SE

Am J Heart Circ Physiol 296(5):H1305-11, 2009

This work examines the capability of CTB-SAP (Cat. #IT-14) to eliminate cardiac sympathetic neurons. The right and left stellate ganglia of rats were each injected with 10 µg of CTB-SAP. Lesioned animals displayed physiolo-gical differences from controls, as well as specific reduction of numbers of neurons in the stellate ganglion and spinal cord.