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Etonogestrel promotes respiratory recovery in an in vivo rat model of central chemoreflex impairment
Janes TA, Cardani S, Saini JK, Pagliardini S (2024) Etonogestrel promotes respiratory recovery in an in vivo rat model of central chemoreflex impairment. Acta Physiol (Oxf) e14093. doi: 10.1111/apha.14093 PMID: 38258900
Objective: Examine the use of progestins and synthetic progestins in the stimulation of breathing, especially after chemoreflexive impairment.
Summary: Central CO2 chemoreflex is important for respiratory control. The retrotrapezoid nucleus is involved in CO2 chemosensitivity where its removal or inhibition attenuates CO2 chemoreflexes and diminishes restful breathing. Progesterone stimulates restful breathing and CO2 chemoreflexes. The authors investigated whether acute or chronic administration of the progestinic drug, etonogestrel, could help in the recovery of respiratory chemoreflexes following lesion of the retrotrapezoid nucleus via a SP-SAP.
Usage: Rats were injected with 26-43.3 ng/ul of SP-SAP (IT-11) or 46.7 ng/ul of Blank-SAP (IT-21), with 150 nl per injection.
Related Products: SSP-SAP (Cat. #IT-11), Blank-SAP (Cat. #IT-21)
Substance P-botulinum mediates long-term silencing of pain pathways that can be re-instated with a second injection of the construct in mice
Maiarù M, Leese C, Silva-Hucha S, Fontana-Giusti S, Tait L, Tamagnini F, Davletov B, Hunt SP (2024) Substance P-botulinum mediates long-term silencing of pain pathways that can be re-instated with a second injection of the construct in mice. J Pain 11 doi: 10.1016/j.jpain.2024.01.331 PMID: 38218509
Summary: The authors discuss how Substance P-Botulinum is used to try to replicate the permanent results achieved with Substance P-Saporin (SP-SAP, SSP-SAP).
Related Products: SSP-SAP (Cat. #IT-11)
See Also:
- Mantyh PW et al. Inhibition of hyperalgesia by ablation of lamina I spinal neurons expressing the substance P receptor. Science 278:275-279, 1997.
- Nichols ML et al. Transmission of chronic nociception by spinal neurons expressing the substance P receptor. Science 286:1558-1561, 1999.
- Brown DC et al. Intrathecal substance p-saporin in the dog: efficacy in bone cancer pain. Anesthesiology 119(5):1178-1185, 2013.
- Wiley RG et al. Anti-nociceptive effects of selectively destroying substance P receptor-expressing dorsal horn neurons using [Sar(9),Met(O(2))(11)]-substance P-saporin: Behavioral and anatomical analyses. Neuroscience 146:1333-1345, 2007.
- Vierck CJ et al. Comparison of operant escape and innate reflex responses to nociceptive skin temperatures produced by heat and cold stimulation of rats. Behav Neurosci. 2004;118(3):627-35.
Neuromedin B-expressing neurons in the retrotrapezoid nucleus regulate respiratory homeostasis and promote stable breathing in adult mice
Souza GMPR, Stornetta DS, Shi Y, Lim E, Berry FE, Bayliss DA, Abbott SBG (2023) Neuromedin B-expressing neurons in the retrotrapezoid nucleus regulate respiratory homeostasis and promote stable breathing in adult mice. J Neurosci JN-RM-0386-23. doi: 10.1523/JNEUROSCI.0386-23.2023 PMID: 37290937
Objective: To develop a transgenic mouse model and demonstrate that retrotrapezoid nucleus (RTN) neurons are fundamental for respiratory homeostasis and mediate the stimulatory effects of CO2 on breathing.
Summary: This study uses a transgenic Nmb-Cre mouse model to demonstrate that RTNNmb neurons are crucial for CO2-dependent breathing in mice. It provides evidence that these neurons play a key role in respiratory homeostasis and might be linked to sleep-disordered breathing in humans. Cre-dependent cell ablation and optogenetics show RTNNmb neurons’ essential function in mediating the hypercapnic ventilatory response, highlighting the importance of these neurons in maintaining eupneic breathing.
Usage: This publication references the use of SSP-SAP (IT-11) to target RTN neurons.
Related Products: SSP-SAP (Cat. #IT-11)
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PARVing the way to cap translation for seizure control
Gross C (2021) PARVing the way to cap translation for seizure control. Epilepsy Curr 21(5):360-362. doi: 10.1177/15357597211027010
Summary: Loss of GABAergic interneurons leads to spontaneous recurrent seizures that persist over months if the amount and spatial spread of initial inhibitory neuron loss is sufficient.
Usage: Intrahippocampal injections of SSP-SAP (0.4 ng/10 nL) were performed using a 0.5-μL Neuros Syringe lowered into four hippocampal sites along both the transverse and longitudinal hippocampal axes bilaterally.
Related Products: SSP-SAP (Cat. #IT-11)
Possible contribution of cerebellar disinhibition in epilepsy
Ming X, Prasad N, Thulasi V, Elkins K, Shivamurthy VKN (2021) Possible contribution of cerebellar disinhibition in epilepsy. Epilepsy Behav 118:107944. doi: 10.1016/j.yebeh.2021.107944
Summary: The authors hypothesize that loss of inhibition from the cerebellum can lead to cortical activation and seizures. An animal study showed microinjection of SSP-SAP produced a selective ablation of hippocampal inhibitory interneurons in vivo and a highly focal disinhibition. These results also demonstrate that the ‘‘epileptic” pathophysiology produced by experimental status epilepticus or head trauma can be replicated by focal interneuron loss, without involving principal cell loss and other interpretive confounds inherent in the use of global neurologic injury models.
Related Products: SSP-SAP (Cat. #IT-11)
See Also:
- Martin JL et al. Focal inhibitory interneuron loss and principal cell hyperexcitability in the rat hippocampus after microinjection of a neurotoxic conjugate of saporin and a peptidase-resistant analog of substance P. J Comp Neurol 436:127-152, 2001.
- Chun E et al. Targeted hippocampal GABA neuron ablation by stable substance P-saporin causes hippocampal sclerosis and chronic epilepsy in rats. Epilepsia 60(5):e52-e57, 2019.
Structural and functional consequences of targeted hippocampal gaba neuron ablation by stable substance p-saporin in rats
Chun E (2020) Structural and functional consequences of targeted hippocampal gaba neuron ablation by stable substance p-saporin in rats. Morehouse School of Medicine Thesis.
Related Products: SSP-SAP (Cat. #IT-11)
Featured Article: Targeted hippocampal GABA neuron ablation produces hippocampal sclerosis, epilepsy, and dissociable effects on the Morris water maze and object-place paired association tasks
Bumanglag AV, Truckenbrod LM, Chun E, Hernandez AR, Federico QP, Maurer AP, Sloviter RS, Burke SN (2019) Featured Article: Targeted hippocampal GABA neuron ablation produces hippocampal sclerosis, epilepsy, and dissociable effects on the Morris water maze and object-place paired association tasks. Targeting Trends 20
Related Products: SSP-SAP (Cat. #IT-11)
Read the featured article in Targeting Trends.
See Also:
Central circuit mechanisms of itch.
Chen XJ, Sun YG (2020) Central circuit mechanisms of itch. Nat Commun 11:3052. doi: 10.1038/s41467-020-16859-5
Summary: The authors summarize the progress in elucidating the neural circuit mechanism of itch at spinal and supraspinal levels.
Related Products: SSP-SAP (Cat. #IT-11)
A role for neurokinin 1 receptor expressing neurons in the paratrigeminal nucleus in bradykinin-evoked cough in guinea-pigs.
Driessen AK, McGovern AE, Behrens R, Moe AAK, Farrell MJ, Mazzone SB (2020) A role for neurokinin 1 receptor expressing neurons in the paratrigeminal nucleus in bradykinin-evoked cough in guinea-pigs. J Physiol 598(11):2257-2275. doi: 10.1113/JP279644
Objective: This study aimed to assess the involvement of paratrigeminal neurokinin 1 receptor neurons in the regulation of cough, breathing and airway defensive responses.
Summary: These findings warrant further investigations into targeting the jugular ganglia and paratrigeminal nucleus as a therapy for treating cough in disease.
Usage: Targeted toxin lesions across three sites of the paratrigeminal nucleus (200nl per injection site).
Related Products: SSP-SAP (Cat. #IT-11)
Episodic stimulation of central chemoreceptor neurons elicits disordered breathing and autonomic dysfunction in volume overload heart failure.
Díaz HS, Andrade DC, Toledo C, Pereyra KV, Schwarz KG, Díaz-Jara E, Lucero C, Arce-Álvarez A, Schultz HD, Silva JN, Takakura AC, Moreira TS, Marcus NJ, Del Rio R (2020) Episodic stimulation of central chemoreceptor neurons elicits disordered breathing and autonomic dysfunction in volume overload heart failure. Am J Physiol Lung Cell Mol Physiol 318(1):L27-L40. doi: 10.1152/ajplung.00007.2019
Objective: To determine the role of the central chemoreflex in the development of respiratory and autonomic dysfunction in volume overload heart failure (HF).
Summary: Episodic hypercapnic stimulation triggers ventilatory plasticity and elicits cardiorespiratory abnormalities in HF that are largely dependent on retrotrapezoid nucleus (RTN) chemoreceptor neurons.
Usage: Bilateral injections of SSP-SAP, 0.6 ng/30 nL, into the RTN were administered to destroy chemoreceptor neurons.
Related Products: SSP-SAP (Cat. #IT-11)