The long-term antinociceptive effect of intrathecal S(+)-ketamine in a patient with established morphine tolerance

Esketamine: Less Drowsiness, More Analgesia

Racemic ketamine is a 1:1 mixture of 2 enantiomers that turn light in opposite direction: Dextrorotatory esketamine is approximately 4 times more affine for the N-methyl-D-aspartate (NMDA) receptor than levorotatory arketamine, which may explain why esketamine is about twice as potent as an analgesic and anesthetic as the racemate. Esketamine has attracted renewed interest in view of the opioid crisis, racemic ketamine's abuse, and esketamine's approval for expanded use. We evaluated the anesthesia literature concerning mental, cardiovascular, cerebral, and antinociceptive effects of esketamine published in English between 1980 and 2022. The review shows that esketamine and racemic ketamine are not "the same" at clinically equivalent analgesic and anesthetic dose: Psychomimetic effects seem to be essentially related to NMDA receptor blockade and esketamine is not devoid of unwanted mental impact. However, it probably involves less cholinergic inhibition. Cognitive disturbances during arousal, awakening, and recovery from the drug are less, and less pronounced with esketamine. The drug allows for an approximately 50% dose reduction in anesthesia and analgesia which goes along with a higher clearance and shorter recovery time as compared to racemic ketamine. In comparison of esketamine with placebo, esketamine shows cardiocirculatory stabilizing and neuroprotective effects which can be seen in anesthesia induction, cardiac surgery, and analgesia and sedation in brain injury. Evidence of esketamine's antinociceptive efficacy is inconsistent, although a recent meta-analysis reports improved pain relief after surgery in a study with short observation time. To better define esketamine's place, direct head-to-head comparison with the racemate at equi-analgesic/anesthetic dose is warranted.

Comparative Efficacy and Safety of 11 Drugs as Therapies for Adults With Neuropathic Pain After Spinal Cord Injury: A Bayesian Network Analysis Based on 20 Randomized Controlled Trials

Objective

To provide an updated analysis of the efficacy and safety of drugs for the management of neuropathic pain (NP) after spinal cord injury (SCI) based on Bayesian network analysis.

Methods

A Bayesian network meta-analysis of literature searches within PubMed, Cochrane Library, Embase, and Web of Science databases from their inception to February 21 2021 was conducted without language restrictions. Paired and network meta-analyses of random effects were used to estimate the total standardized mean deviations (SMDs) and odds ratios (ORs).

Results

A total of 1,133 citations were identified and 20 RCTs (including 1,198 patients) involving 11 drugs and placebos for post-SCI NP selected. The 5 outcomes from all 11 drugs and placebos had no inconsistencies after Bayesian network analysis. BTX-A gave the most effective pain relief for the 4 weeks, following a primary outcome. No significant differences were found among drugs with regard to adverse events of the primary outcome. Gabapentin, BTX-A, and pregabalin were found to be the most helpful in relieving secondary outcomes of mental or sleep-related symptoms with differences in SMDs, ranging from −0.63 to −0.86. Tramadol triggered more serious adverse events than any of the other drugs with differences in ORs ranging from 0.09 to 0.11.

Conclusion

BTX-A, gabapentin, pregabalin, amitriptyline, ketamine, lamotrigine, and duloxetine were all effective for NP management following SCI. Lamotrigine and gabapentin caused fewer side effects and had better efficacy in relieving mental or sleep-related symptoms caused by SCI-related NP. Tramadol, levetiracetam, carbamazepine, and cannabinoids could not be recommended due to inferior safety or efficacy.

Systematic Review Registration

[https://inplasy.com/inplasy-2020-7-0061/], identifier [INPLASY202070061].

Effect of morphine and a low dose of ketamine on the T cells of patients with refractory cancer pain in vitro

The combination of morphine and ketamine is considered safe and efficacious in many patients. However, a considerable number of immunomodulatory effects have been reported to be produced by both morphine and ketamine. The aim of the present study was to assess the direct effect of morphine and a low dose of ketamine on the T cells of patients with refractory cancer pain in vitro. Venous blood was obtained from patients with refractory cancer pain and peripheral blood mononuclear cells were isolated using the Ficoll-Hypaque density gradient method. Anti-CD3 beads were used to isolate T cells by positive selection. Subsequently, the T cells were treated with vehicle, 200 ng/ml of morphine or 200 ng/ml of morphine + 100 ng/ml ketamine for 24 h, following which the cells were stimulated with anti-CD3 and anti-CD28. Flow cytometric analysis of CD3⁺ T cells, and interleukin (IL)-2 and interferon (IFN)-γ in the supernatant, reverse transcription-quantitative PCR analysis for the detection of IL-2 and IFN-γ and western blotting for the detection of p65 nuclear factor (NF)-κB were performed. In vitro, the CD4⁺ and CD8⁺ T cell counts, CD4⁺/CD8⁺ ratio, secretion of IL-2 and IFN-γ in the supernatant, mRNA expression levels of IL-2 and IFN-γ and expression of p65 NF-κB were significantly decreased following treatment with morphine and morphine + ketamine, compared with results in the control group (all P<0.05). However, there was no significant difference between treatment with morphine and that with morphine + ketamine. Treatment with morphine + ketamine in vitro decreased the immune functions of patients with refractory cancer pain, although the effect of treatment with morphine and a low dose of ketamine did not differ significantly from that with morphine treatment alone.

Epidural ketamine in post spinal cord injury-related chronic pain

Aim:

This study was to identify the safety and efficacy of adding epidural N-methyl-D-aspartate receptor antagonists (ketamine) to oral gabapentin for the treatment of post spinal cord injury-related chronic pain.

Materials and Methods:

Forty patients in the age range of 18–50 years with a diagnosis of neuropathic pain secondary to spinal cord injury were randomized into two equal groups. Group I received 0.2 mg/Kg of preservative-free ketamine (2 ml) single bolus epidural injection and gabapentin 300 mg three times daily. Group II received isotonic saline 0.9% (2 ml) single bolus epidural injection and gabapentin 300 mg three times daily. Pain scores were evaluated pre-injection, 7, 15, 30,45 and 60 days post injection. Patients were asked about any side-effects occurred during follow-up period.

Results:

At all time points examined, pain scores were significantly lower in both groups than pre-injection values (P < 0.0001). Pain scores were significantly lower in Group I than in Group II at 7, 15, 30 days after injection (P 0.02, < 0.0001, =0.0001 respectively), but no statistically significant difference was detected between groups at 45, 60 days post injection (P = 0.54, =0.25), there was no statistically significant difference regarding incidence of side-effects in both groups.

Conclusion:

Epidurally administrated ketamine seems to be a safe adjunct to gabapentin in post spinal cord injury-related chronic pain. However, its analgesic efficacy was limited to 30 days after injection.

Selective antinociceptive effects of a combination of the N-methyl-D-aspartate receptor peptide antagonist [Ser(1)]histogranin and morphine in rat models of pain

Numerous rather than a few analgesic endogenous neuropeptides are likely to work in concert in vivo in ameliorating pain. Identification of effective neuropeptide combinations would also facilitate the development of gene or cell-based analgesics. In this study, opioid peptides endomorphin-1 (EM-1) and endomorphin-2 (EM-2) and the peptide histogranin analogue [Ser¹]histogranin (SHG), which possess activity as an N-methyl-d-aspartate (NMDA) receptor antagonist, were intrathecally (i.t.) injected alone and in combination in rat models of acute and persistent pain. None of the peptides when injected alone altered hind paw responses of uninjured rats to acute noxious stimulation. EM-1 and EM-2 showed divergent efficacies in the persistent pain models. For example, EM-1 injected alone was antinociceptive in rats with neuropathic pain, whereas EM-2 demonstrated no efficacy. Demonstration of synergism was also divergent across the models. For example, while SHG combined with EM-1 did not alter the efficacy of EM-1 in rats with neuropathic pain, SHG significantly increased the efficacy of EM-1 in the formalin test. By contrast, the potency and efficacy of the peptides alone and combinations were much less than those of the reference analgesic morphine. Furthermore, morphine combined with the clinically used NMDA receptor antagonist ketamine showed synergism across a broad range of pain states. While the current set of neuropeptides could serve as a basis for analgesic therapeutics, there could be other neuropeptides with greater efficacy and potency and broader therapeutic application.

Evaluation of the analgesic effect of ketamine as an additive to intrathecal bupivacaine in patients undergoing cesarean section

OBJECTIVE

Nowadays, conventional analgesic agents, which are widely used for pain relief after cesarean section, provide suboptimal analgesia with occasional serious side effects. We designed a randomized, double-blind, placebo-controlled study to evaluate the analgesic efficacy of intrathecal ketamine added to bupivacaine after cesarean section.

METHODS

Sixty patients scheduled for cesarean section under spinal anesthesia were randomly allocated to one of the two groups to receive either bupivacaine 10 mg combined with 0.1 mg/kg ketamine, or bupivacaine 10 mg combined with 0.5 mL distilled water intrathecally. The time to the first analgesic request, analgesic requirement in the first 24 hours after surgery, onset times of sensory and motor blockades, the durations of sensory and motor blockades, and the incidences of adverse effects such as hypotension, ephedrine requirement, bradycardia, and hypoxemia, were recorded.

RESULTS

Patients who received ketamine had a significantly prolonged duration of anesthesia compared with those who did not in the control group [95% confidence intervals (CI) 195-217; p = 0.001]. The mean time to the first analgesic request was also significantly longer in ketamine group (95% CI 252.5-275; p < 0.001). The total analgesic consumption in the 24 hours following surgery significantly lessened in the ketamine group compared with that of the control group (95% CI 2-2.5; p < 0.001). The two groups did not differ significantly in intraoperative and postoperative side effects.

CONCLUSION

Intrathecal ketamine 0.1 mg/kg co-administered with spinal bupivacaine elongated the time to the first analgesic request and lessened the total analgesic consumption in the first 24 postoperative hours in comparison with bupivacaine alone in the control group following elective cesarean delivery.

Ketamine induces apoptosis via the mitochondrial pathway in human lymphocytes and neuronal cells

BACKGROUND

Ketamine has been shown to have neurotoxic properties, when administered neuraxially. The mechanism of this local toxicity is still unknown. Therefore, we investigated the mechanism of cytotoxicity in different human cell lines in vitro.

METHODS

We incubated the following cell types for 24 h with increasing concentrations of S(+)-ketamine and racemic ketamine: (i) human Jurkat T-lymphoma cells overexpressing the antiapoptotic B-cell lymphoma 2 protein, (ii) cells deficient of caspase-9, caspase-8, or Fas-associated protein with death domain and parental cells, and (iii) neuroblastoma cells (SHEP). N-Methyl-d-aspartate (NMDA) receptors and caspase-3 cleavage were identified by immunoblotting. Cell viability and apoptotic cell death were evaluated flowcytometrically by Annexin V and 7-aminoactinomycin D double staining. Mitochondrial metabolic activity and caspase-3 activation were measured.

RESULTS

Ketamine, in a concentration-dependent manner, induced apoptosis in lymphocytes and neuroblastoma cell lines. Cell lines with alterations of the mitochondrial pathway of apoptosis were protected against ketamine-induced apoptosis, whereas alterations of the death receptor pathway did not reduce apoptosis. S(+)-Ketamine and racemic ketamine induced the same percentage of cell death in Jurkat cells, whereas in neuroblastoma cells, S(+)-ketamine was slightly less toxic.

CONCLUSIONS

Ketamine at millimolar concentrations induces apoptosis via the mitochondrial pathway, independent of death receptor signalling. At higher concentrations necrosis is the predominant mechanism. Less toxicity of S(+)-ketamine was observed in neuroblastoma cells, but this difference was minor and therefore unlikely to be mediated via the NMDA receptor.

Brief review: Perioperative management of the patient with chronic non-cancer pain

PURPOSE

Both opioid and non-opioid medications are being utilized increasingly in the treatment of chronic non-cancer pain, and the number of surgical patients receiving large regular doses of opioids is ever-expanding. The perioperative pain control of these patients is often challenging, and is broadening the role of the anesthesiologist as 'perioperative physician'. These patients need to be identified before surgery to plan optimal pain control postoperatively. The purpose of this review is to provide an update on the important considerations in managing the chronic non-cancer pain patient receiving high dose opioids and other adjunctive medications/analgesics.

SOURCE

English language articles published between June 1980 and May 2006 were identified by a computerized Medline search using keywords (1/2)chronic pain(1/2), (1/2)opioid dependent(1/2) and (1/2)perioperative(1/2). This same search strategy was repeated and updated using both Medline and Embase. All relevant publications were retrieved and their bibliographies were scanned for additional sources.

PRINCIPAL FINDINGS

Although an increasingly common problem for the acute pain service, there is very little published on this topic. Key points include the concept of opioid equivalency, tolerance, the role of adjunctive medications, and the need for good communication between the surgical team, the acute pain service and the patient who is often anxious about the upcoming procedure due to previous unpleasant experiences with poor pain control in hospital.

CONCLUSION

Clinical care of the opioid-dependent patient in the perioperative period can be a daunting task. Education to all staff involved in this area needs to be enhanced to improve outcome and patient satisfaction.

The role of ketamine in pain management

Ketamine is a dissociative anaesthetic; its mechanism of action is primarily an antagonism of the N-methyl-D-aspartate (NMDA) receptor. The role of ketamine, in particular in lower sub-anaesthetic doses, has recently gained increasing interest in pain management. It has been studied in a considerable number of trials and analysed in meta-analyses and systematic reviews. Based on these data, the primary role of ketamine in such low doses is as an 'anti-hyperalgesic', 'anti-allodynic' or 'tolerance-protective' agent. It therefore has a role in the treatment of opioid resistant or 'pathological' pain (central sensitisation with hyperalgesia or allodynia, opioid induced hyperalgesia, neuropathic pain) rather than as an 'analgesic' in its own right. Low dose ketamine also has 'preventive analgesia' properties. Furthermore, in higher doses it provides effective and safe sedation and analgesia for painful procedures. The place of ketamine in the treatment of chronic pain and the effects of long-term medicinal use remain unclear.

Ketamine impairs excitability in superficial dorsal horn neurones by blocking sodium and voltage-gated potassium currents

Ketamine shows, besides its general anaesthetic effect, a potent analgesic effect after spinal administration. We investigated the local anaesthetic-like action of ketamine and its enantiomers in Na+ and K+ channels and their functional consequences in dorsal horn neurones of laminae I-III, which are important neuronal structures for pain transmission receiving most of their primary sensory input from Adelta and C fibres. Combining the patch-clamp recordings in slice preparation with the 'entire soma isolation' method, we studied action of ketamine on Na+ and voltage-activated K+ currents. The changes in repetitive firing behaviour of tonically firing neurones were investigated in current-clamp mode after application of ketamine. Concentration-effect curves for the Na+ peak current revealed for tonic block half-maximal inhibiting concentrations (IC50) of 128 microM and 269 microM for S(+) and R(-)-ketamine, respectively, showing a weak stereoselectivity. The block of Na+ current was use-dependent. The voltage-dependent K+ current (K(DR)) was also sensitive to ketamine with IC50 values of 266 microM and 196 microM for S(+) and R(-)-ketamine, respectively. Rapidly inactivating K+ currents (K(A)) were less sensitive to ketamine. The block of K(DR) channels led to an increase in action potential duration and, as a consequence, to lowering of the discharge frequency in the neurones. We conclude that ketamine blocks Na+ and K(DR) channels in superficial dorsal horn neurones of the lumbar spinal cord at clinically relevant concentrations for local, intrathecal application. Ketamine reduces the excitability of the neurones, which may play an important role in the complex mechanism of its action during spinal anaesthesia.

Neuropathological findings after continuous intrathecal administration of S(+)-ketamine for the management of neuropathic cancer pain

Questions have been raised about the potential neurotoxicity of the neuraxial use of ketamine although ketamine and its active enantiomer S(+)-ketamine have been used intrathecally and epidurally (caudally) for the management of perioperative pain and in a variety of chronic pain syndromes. Clinical experience following neuraxial administration of S(+)-ketamine has been documented without reference to local central nervous system toxicity following this approach. In addition, there are no preclinical safety data regarding stability, compatibility, and neurotoxicity on intrathecal use of single S(+)-ketamine or combinations of S(+)-ketamine, morphine, bupivacaine, and clonidine. In the present case, the continuous intrathecal administration of S(+)-ketamine, in combination with morphine, bupivacaine, and clonidine resulted in adequate pain relief in a patient suffering from intractable neuropathic cancer pain. However, postmortem observation of the spinal cord and nerve roots revealed severe histological abnormalities including central chromatolysis, nerve cell shrinkage, neuronophagia, microglial upregulation, and gliosis. Based on our results, neuraxial administration of S (+)-ketamine cannot be recommended for clinical practise before a systematic study of toxicology of neuraxial S(+)-ketamine in animals or humans has been performed.

Long-term intrathecal S(+)-ketamine in a patient with cancer-related neuropathic pain

Neuropathic pain sometimes needs invasive pain therapy. We present the case of a patient with cancer-related neuropathic pain untreatable with conventional pain therapy after tumour-embolization. The patient was treated successfully with intrathecal (i.t.) administration of S(+)-ketamine, in addition to morphine. Plasma concentrations of S(+)-ketamine were measured regularly throughout the treatment. Continuous i.t. administration of S(+)-ketamine over a period of 3 months demonstrated low plasma levels and no unwanted side-effects.

Therapie extremer Tumorschmerzen mit Morphin und (S)-Ketamin

We are reporting on the case of an 11-year old girl with a malignant tumour. The extreme pain throughout the body could not be treated by conventional methods. By intravenous application of a morphine and s-ketamine mixture we were able to achieve a very effective analgesic result. Apart from the opiate effect of the morphine the decisive factor was the NMDA-antagonism of the s-ketamine. The latter suppresses central sensitisation and chronic pain and reduces or even prevents the development of opioid tolerance. It was possible to use smaller opiate doses more effectively, thus reducing the side effects of the pain therapy. Under associated whole-body thermochemotherapy the girl experienced general pain relief and we were able to return to conventional therapy with a fentanyl plaster.

Potentiation of spinal N-methyl-D-aspartate-mediated nociceptive transmission by cocaine-regulated and amphetamine-regulated transcript peptide in rats

The present study examined the effects of cocaine-regulated and amphetamine-regulated transcript peptide (CARTp) fragment 55-102, on N-methyl-D-aspartate (NMDA)-mediated nociceptive transmission in vivo and in vitro. In-vivo experiments were conducted in Sprague-Dawley rats to evaluate the effects of CARTp on thermal hyperalgesia induced by NMDA or alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA). Intrathecal NMDA (1, 2, 4 nmol) or AMPA (0.5, 1, 2 nmol) dose-dependently decreased the tail-flick latency. Intrathecal CARTp was without effect on the tail-flick latency. Interestingly, it significantly enhanced NMDA-induced, but not AMPA-induced, nociceptive effects. The in-vitro effects of CARTp on NMDA-induced or AMPA-induced depolarizations in substantia gelatinosa neurons were studied in rat spinal cord slices. CARTp (100, 300 nM), which caused no significant change of membrane potentials, increased the amplitude of NMDA-induced depolarizations in substantia gelatinosa neurons with little effect on AMPA-induced depolarizations. The present study demonstrates that exogenously applied CARTp selectively facilitates NMDA receptor-mediated nociceptive transmission.

Investigation of the potentiation of the analgesic effects of fentanyl by ketamine in humans: a double-blinded, randomised, placebo controlled, crossover study of experimental pain[ISRCTN83088383]

BACKGROUND: Despite preclinical evidence suggesting a synergistic interaction between ketamine and opioids promoting analgesia, several clinical trials have not identified dosing regimens capable of eliciting a benefit in the co-administration of ketamine with opioids. METHODS: Ten healthy volunteers participated in a double blinded, randomised, placebo controlled, crossover laboratory study in order to determine whether a low dose of ketamine potentiated the antinociceptive effect of fentanyl without causing an increase in sedative effects. A battery of tests was used to assess both nociception and sedation including electrical current, pressure, thermal stimuli, psychometric tests, and both subjective and objective scores of sedation. Target controlled infusions of the study drugs were used. Ketamine and fentanyl were administered alone and in combination in a double-blinded randomised crossover design. Saline was used as the control, and propofol was used to validate the tests of sedation. Cardiovascular and respiratory parameters were also assessed. RESULTS: The electrical current pain threshold dose response curve of fentanyl combined with ketamine was markedly steeper than the dose response curve of fentanyl alone. While a ketamine serum concentration of 30 ng/ml did not result in a change in electrical pain threshold when administered alone, when it was added to fentanyl, the combination resulted in greater increase in pain threshold than that of fentanyl administered alone. When nociception was assessed using heat and pressure stimuli, ketamine did not potentiate the anti-nociceptive effect of fentanyl. There was no difference between the sedative effect of fentanyl and fentanyl in combination with ketamine as assessed by both subjective and objective measures of sedation. Cardiovascular and respiratory parameters were unaffected by the study drugs at the doses given. CONCLUSION: A serum concentration of ketamine that did not alter indices of sedation potentiated the antinociceptive effect of fentanyl. This potentiation of antinociception occurred without an increase in sedation suggesting that low steady doses of ketamine (30-120 ng/ml) might be combined with mu opioid agonists to improve their analgesic effect in a clinical setting. (296 words).

Polyanalgesic Consensus Conference 2003: an update on the management of pain by intraspinal drug delivery-- report of an expert panel

Intraspinal drug infusion using fully implantable pump and catheter systems is a safe and effective therapy for selected patients with chronic pain. The options for this approach are increasing, as drugs that are commercially available for systemic administration are adapted to this use and other drugs that are in development specifically for intraspinal administration become available. In 2000 a Polyanalgesic Consensus Conference was organized to evaluate the existing literature and develop guidelines for drug selection. The major outcome of this effort, an algorithm for drug selection, was based on the best available evidence at the time. Rapid changes have occurred in the science and practice of intraspinal infusion and a Polyanalgesic Consensus Conference 2003 was organized to pursue the following goals: 1) to review the literature on intraspinal drug infusion since 1999, 2) to revise the 2000 drug-selection algorithm, 3) to develop guidelines for optimizing drug dosage and concentration, 4) to create a process for documenting minimum evidence supporting the use of a drug for intraspinal infusion, and 5) to clarify issues pertaining to compounding of drugs. Based on the best available evidence and expert opinion, consensus recommendations were developed in all these areas. The panel's conclusions may provide a foundation for clinical practice and a rational basis for new research.

Treatment of neuropathic cancer pain with continuous intrathecal administration of S +-ketamine

The effective treatment of patients suffering from neuropathic cancer pain remains a clinical challenge. When patients experience either insufficient analgesia or problematic side-effects after opioid administration, intrathecal administration of morphine and other medications such as bupivacaine and clonidine may offer significant advantages. Additionally, ketamine, a non-competitive N-methyl-D-Aspartate-receptor antagonist is able to alter pain perception at the spinal level. Because of the potential neurotoxicity after neuraxial use of racemic ketamine, intrathecal administration of the preservative-free active compound, S (+)-ketamine may be a valuable alternative. In this paper, we present a patient with severe neuropathic cancer pain successfully treated by continuous intrathecal infusion of morphine, bupivacaine, clonidine and S (+)-ketamine. Moreover, quality of life measurements before and 3 weeks after the start of spinal treatment revealed an improvement in pain relief and a higher overall quality of life. No clinical signs of neurologic deficit were observed during spinal treatment with S (+)-ketamine. However, the continuous intrathecal administration of S (+)-ketamine should be considered as the last resort because there are no preclinical safety data with relevant concentrations on intrathecal use of S (+)-ketamine.

Intrathecal drug delivery 2002

BACKGROUND

Intrathecal drug delivery has been used clinically since the 1970's. Significant clinical advances have been made combining new technology with pharmacology and surgery. Continuous infusion of medication for both analgesia and spasticity has become a part of the armamentarium for specialists in these areas. Significant recent advances in technology promise further enhancements and improvements for intrathecal therapy.

METHODS

A review of the literature combined with 20 years personal experience with intrathecal drug delivery.

FINDINGS/DISCUSSION

Intrathecal therapy has established a role in the treatment of malignant pain, benign pain and severe spasticity. Significant literature and the current state of practice in the United States are reviewed. Recent therapeutic enhancements are discussed, and a wish list of future technological enhancements presented.

Endogenous opiates and behavior: 2001

This paper is the twenty-fourth installment of the annual review of research concerning the opiate system. It summarizes papers published during 2001 that studied the behavioral effects of the opiate peptides and antagonists. The particular topics covered this year include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors (Section 2), and the roles of these opioid peptides and receptors in pain and analgesia (Section 3); stress and social status (Section 4); tolerance and dependence (Section 5); learning and memory (Section 6); eating and drinking (Section 7); alcohol and drugs of abuse (Section 8); sexual activity and hormones, pregnancy, development and endocrinology(Section 9); mental illness and mood (Section 10); seizures and neurologic disorders (Section 11); electrical-related activity and neurophysiology (Section 12); general activity and locomotion (Section 13); gastrointestinal, renal and hepatic functions (Section 14); cardiovascular responses (Section 15); respiration and thermoregulation (Section 16); and immunological responses (Section 17).