Behavioral evidence for two-stage sleep in spiders

  Behavioral evidence for two-stage sleep in spiders Abstract Sleep is a fundamental behavioral state found across the animal kingdom, yet most of what we know about sleep is heavily vertebrate-biased. Studies are scarce or nonexistent in all but a few invertebrate lineages. A recent study of an REM sleep-like behavior in a jumping spider has reported unexpected parallels to sleep expression in vertebrates. So far, experimental evidence that these behavioral indicators truly represent sleep was lacking in spiders. Here, we present a comprehensive investigation into sleep behavior in the spider Portia fimbriata (Salticidae). We demonstrate diurnal activity, a free-running circadian rhythm, robust sleep architecture, regularly occurring REM-like behaviors, elevated arousal thresholds during those REM-like states, as well as rebound effects following sleep disruption. We conclude that the behavior we observe in spiders is behavioral sleep, providing evidence for an REM-like sleep sub...

Toxic myocarditis following scorpion sting in a child: a case report and pediatric management approach

 


Toxic myocarditis following scorpion sting in a child: a case report and pediatric management approach

Case presentation

A 3.5-year-old girl with no prior medical history was brought to the emergency department of a hospital in Birjand, Iran, at 23:50 by ambulance following a scorpion sting by a Hemiscorpius lepturus scorpion (locally known as “Gadim”). The sting occurred on the dorsal surface of her right upper limb. The patient presented with decreased levels of consciousness, hypotension, and anaphylactic shock. She complained of severe pain at the sting site and had experienced one episode of non-projectile, bilious, and non-bloody vomiting.

At the sting site, which appeared as a visible dot adjacent to a vein, erythema, edema, and mild tenderness were observed. Neurovascular examination of the affected hand was reported as normal. Neurologically, the patient was neither conscious nor oriented, with closed eyes, no response to verbal stimuli, and only localization to painful stimuli. The attending nurse documented an initial Glasgow Coma Scale (GCS) score of 10. Spontaneous and normal breathing was noted, and the pupils were bilaterally equal and reactive to light.


The patient was promptly placed under cardiopulmonary monitoring. Upon admission, her vital signs were as follows: respiratory rate (RR) of 30 breaths/min, heart rate (HR) of 150 beats/min, temperature (T) of 34.7 °C, oxygen saturation (SpO2) of 89%, and blood pressure (BP) of 70/42 mmHg. An emergency medicine specialist evaluated the patient, who was instructed to remain NPO, and an intravenous line was established. At the time of admission, she received two intramuscular doses of epinephrine (0.1 mg/kg, 1:1000), and 5 mg of intravenous chlorpheniramine (equivalent to 0.5 cc from the 10 mg/ml ampoule available in the Iranian pharmacopeia), and three vials of scorpion antivenom, along with intravenous normal saline (approximately 1 L over one hour) as part of fluid resuscitation to correct severe hypotension (BP 70/42 mmHg) and anaphylactic shock. Initial laboratory tests, including CBC, Diff, BUN, Cr, Bs, Na, K, Mg, Troponin I, Creatine Phosphokinase (CPK), N-terminal pro–B-type natriuretic peptide (NT-proBNP), and liver enzymes, were performed and sent for analysis. Based on clinical and paraclinical findings, no evidence of hemolysis or rhabdomyolysis was observed throughout the hospital stay. Chest X-ray (CXR) performed as part of the diagnostic evaluation, showing normal results (Fig. 1).

Akbari, A., Niksefat, F., Mirshahi, A. et al. Toxic myocarditis following scorpion sting in a child: a case report and pediatric management approach. BMC Pediatr 25, 900 (2025). https://doi.org/10.1186/s12887-025-06266-4