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Comparison of recovery of sheep, goats, and calves from reversible electrical head-only and head-to-body stunning for halal meat production

Beausoleil NJ, Farouk MM, Webster J, Johnson CB, Dowling S, Sazili AQ, et al.

N Z Vet J, 2024 Sep;72(5):288-299.
PMID: 38946044 DOI: 10.1080/00480169.2024.2367532

AIMS: To compare the recovery of lambs, goats, and calves from head-only (HO) or high-frequency head-to-body stunning and evaluate the complementary use of behaviour and electroencephalography (EEG) to assess return to consciousness after electrical stunning in these species.
METHODS: Six-month-old lambs, adult goats and calves (< 7 days old) were subjected to reversible head-only stunning (50 Hz, 1 A, 2 seconds) or reversible high-frequency head-to-body stunning (RHTB: HO followed by 2,000 Hz, 2 A, 4-second stun to body). Following stunning, behavioural recovery was assessed in 21 lambs, 22 goats, and 20 calves. Latencies to first perform behaviours (end of convulsions, head lift, attempt to right, successful righting, attempt to stand, successful standing) after stunning were scored from video recordings. Recovery of electrical brain activity indicative of consciousness was assessed using EEG in a separate cohort of minimally-anaesthetised lambs, goats and calves (n = 20 per species). EEG traces collected before and after stunning were classified as normal, epileptiform, isoelectric, or transitional activity. Following stunning, the duration of epileptiform and isoelectric activity combined (states of brain activity incompatible with conscious awareness) was calculated, as was latency to return of normal (pre-stun) EEG.
RESULTS: The RHTB stun was reversible in all three species, although one sheep failed to recover and was euthanised. Both methods caused tonic and clonic convulsions in all species. Behavioural recovery of sheep and calves was similar for both methods while goats took longer to recover from RHTB than HO stunning. There was no evidence of differences between methods in the duration of EEG incompatible with consciousness or the latency to recovery of normal EEG.
CONCLUSIONS: Head-to-body stunning as applied here produced a reversible electrical stun in lambs, adult goats and young calves, although the benefits in terms of meat quality and operator safety are uncertain. Goats took longer to recover behaviourally from head-to-body stunning, possibly due to disrupted motor function, but there was no indication that post-stun unconsciousness lasted longer than following head-only stunning in any species. The normal behaviour for the animals' developmental age should be considered when deciding on behavioural indicators of recovery. The minimal anaesthesia model provided excellent quality EEG data that was valuable for interpretation of the behavioural responses.
CLINICAL RELEVANCE: For the purposes of pre-slaughter stunning of sheep, goats and young calves, recovery appears comparable between the two methods, with all but 1/63 animals in the behaviour study recovering normal function.

Matched MeSH terms: Electroshock/veterinary
Amnesic effects of electroshock and anoxia on conditioned taste aversion learning in rats

Banerjee U, Das P

Behav Processes, 1977 Jun;2(2):175-86.
PMID: 24896436 DOI: 10.1016/0376-6357(77)90019-5

Albino Wistar rats of both sexes were given a conditioned taste aversion training (CTA). Saccharin was used as the conditional stimulus (CS) and apomorphine-induced illness as the unconditional stimulus (US) on day 4. Amnestic treatment with electroconvulsive shock (ECS) or nitrogen anoxia were given to the rats at various points within the 180-min long CS-US interval as well as after the US. They were reexposed to the CS on days 5 and 6 in order to evaluate CTA and its extinction respectively. Apomorphine injection alone produced significant CTA as long as the CS-US interval was less than 120 min but not beyond it. Saline injections, with or without amnestic treatments, produced only an adaptation to and preference for saccharin. ECS could prevent CTA when delivered within 85 min before or 110 min after the US. Anoxia was effective at a much shorter range of time than ECS. The results are discussed in the perspectives of neophobia, saccharin aversion, amnestic agents and the character as well as gradients of amnesia produced.

Matched MeSH terms: Electroshock
Design, Synthesis, and Pharmacological Screening of Pyridazinone Hybrids as Anticonvulsant Agents

Partap S, Yar MS, Hassan MZ, Akhtar MJ, Siddiqui AA

Arch Pharm (Weinheim), 2017 Oct;350(10).
PMID: 28863231 DOI: 10.1002/ardp.201700135

A series of new hybrid benzimidazole containing pyridazinones derivatives were designed and synthesized in accordance with the pharmacophoric requirements essential for the anticonvulsant activity. The synthesized compounds were evaluated for anticonvulsant activity on mice by the gold standard maximal electroshock (MES) and subcutaneous pentylenetetrazole (scPTZ)-induced seizure models. Among the compounds tested, SS-4F showed significant anticonvulsant activity in both the screens with ED50 values of 25.10 and 85.33 mg/kg in the MES and scPTZ screens, respectively. Compound SS-4F emerged as safer and effective anticonvulsant due to its several-fold higher protective indices. Further, the gamma-aminobutyric acid (GABA) estimation result showed a marked increase in the GABA level (1.7-fold) as compared to the control, which was further confirmed by good binding properties with the GABAA receptor.

Matched MeSH terms: Electroshock
Effect of fluoxetine on maximal electroshock seizures in mice: acute vs chronic administration

Raju SS, Noor AR, Gurthu S, Giriyappanavar CR, Acharya SB, Low HC, et al.

Pharmacol Res, 1999 Jun;39(6):451-4.
PMID: 10373242

There are no definite reports regarding the effects of chronic fluoxetine on animal models of epilepsy. Since chronically administered fluoxetine, in comparison to acutely administered fluoxetine has different effects on CNS, the present study was undertaken to investigate the effect of acute and chronic fluoxetine pretreatment, on a median anticonvulsant dose (ED50) of phenytoin in male ICR albino mice. Additionally, the effects of fluoxetine pretreatment on median convulsive current (CC50) in the presence and absence of phenytoin were investigated and results were compared. The maximal electroshock seizure (MES) test was used to estimate the ED50of phenytoin. The electroshock threshold test was used to estimate CC50. ED50and CC50values were calculated by probit analysis. The effects of the chronic and acute fluoxetine groups on the ED50of phenytoin were significantly different (P<0.05), and on CC50this difference was not statistically significant. Chronic fluoxetine insignificantly increased the ED50of phenytoin and decreased the CC50while acute fluoxetine decreased the ED50of phenytoin and increased the CC50. Our results indicate that chronic fluoxetine does not have an antiepileptic property and it may have dubious proconvulsant properties, contrary to acute fluoxetine.

Matched MeSH terms: Electroshock
Effect of propranolol and nifedipine on maximal electroshock-induced seizures in mice: individually and in combination

Raju SS, Gopalakrishna HN, Venkatadri N

Pharmacol Res, 1998 Dec;38(6):449-52.
PMID: 9990653

A comparative effect of propranolol and nifedipine administered individually and in combination at graded dose levels; and that of phenytoin at 30 mg kg-1 on maximal electroshock (MES)-induced seizure in mice was investigated. Propranolol in doses of 10 mg kg-1 and 20 mg kg-1, and nifedipine in doses of 8 mg kg-1 and 16 mg kg-1 significantly modified MES activity. Propranolol (40 mg kg-1), and a combination of propranolol (20 mg kg-1) and nifedipine (8 mg kg-1), produced antiMES activity, which was comparable to that of phenytoin (30 mg kg-1). In mice treated with propranolol and nifedipine combination, the tonic flexor and tonic extensor phase ratios (F/E ratio) were significantly higher than individual drug responses. Our findings suggest that a combination of propranolol and nifedipine has either synergistic or an additive effect in controlling MES-induced seizures in mice.

Matched MeSH terms: Electroshock
Fulltext Brain Lipopolysaccharide Preconditioning-Induced Gene Reprogramming Mediates a Tolerance State in Electroconvulsive Shock Model of Epilepsy

Amini E, Golpich M, Farjam AS, Kamalidehghan B, Mohamed Z, Ibrahim NM, et al.

Front Pharmacol, 2018;9:416.
PMID: 29765321 DOI: 10.3389/fphar.2018.00416

There is increasing evidence pointing toward the role of inflammatory processes in epileptic seizures, and reciprocally, prolonged seizures induce more inflammation in the brain. In this regard, effective strategies to control epilepsy resulting from neuroinflammation could be targeted. Based on the available data, preconditioning (PC) with low dose lipopolysaccharide (LPS) through the regulation of the TLR4 signaling pathway provides neuroprotection against subsequent challenge with injury in the brain. To test this, we examined the effects of a single and chronic brain LPS PC, which is expected to lead to reduction of inflammation against epileptic seizures induced by electroconvulsive shock (ECS). A total of 60 male Sprague Dawley rats were randomly assigned to five groups: control, vehicle (single and chronic), and LPS PC (single and chronic). We first recorded the data regarding the behavioral and histological changes. We further investigated the alterations of gene and protein expression of important mediators in relation to TLR4 and inflammatory signaling pathways. Interestingly, significant increased presence of NFκB inhibitors [Src homology 2-containing inositol phosphatase-1 (SHIP1) and Toll interacting protein (TOLLIP)] was observed in LPS-preconditioned animals. This result was also associated with over-expression of IRF3 activity and anti-inflammatory markers, along with down-regulation of pro-inflammatory mediators. Summarizing, the analysis revealed that PC with LPS prior to seizure induction may have a neuroprotective effect possibly by reprogramming the signaling response to injury.

Matched MeSH terms: Electroshock
Antibacterial, antifungal and anticonvulsant evaluation of novel newly synthesized 1-[2-(1H-tetrazol-5-yl)ethyl]-1H-benzo[d][1, 2,3]triazoles

Rajasekaran A, Murugesan S, AnandaRajagopal K

Arch Pharm Res, 2006 Jul;29(7):535-40.
PMID: 16903071

Several novel 1-[2-(1H-tetrazol-5-yl) ethyl]-1H-benzo[d][1,2,3]triazoles (3a-h) have been synthesized by the condensation of 1-[2-(1H-tetrazol-5-yl)-ethyl]-1H-benzotriazole (2) and appropriate acid chlorides. 1-[2-(1H-tetrazol-5-yl)-ethyl]-1H-benzotriazole (2) was synthesized by reacting 3-(1H-benzo[d][1,2,3]triazol-1-yl)propanenitrile with sodium azide and ammonium chloride in the presence of dimethylformamide. The synthesized compounds were characterized by IR and PMR analysis. The titled compounds were evaluated for their in-vitro antibacterial and antifungal activity by the cup plate method and anticonvulsant activity evaluated by the maximal electroshock induced convulsion method in mice. All synthesized compounds exhibited moderate antibacterial activity against Bacillus subtilis and moderate antifungal activity against Candida albicans. Compounds 5-(2-(1H-benzo[d][1,2,3]triazo-1-yl)ethyl)-1H-tetrazol-1-yl)(4-aminophenyl)methanone 3d and 5-(2-(1 H-benzo[d][1,2,3]triazo-1-yl)ethyl)-1H-tetrazol-1-yl)(2-aminophenyl)methanone 3e elicited excellent anticonvulsant activity.

Matched MeSH terms: Electroshock