The present disclosure provides, according to some embodiments, methods and systems for selectively reducing, blocking or inhibiting at least part of the neural activity in an organ of a subject. In preferred embodiments, the method and system are used for selectively blocking at least part of the neural activity in a duodenum of a subject in need thereof. According to some embodiments, the selective blocking occurs through use of laser radiation. According to some embodiments, the selective blocking occurs through use of ultrasound energy. According to some embodiments, the selective blocking comprises causing damage to at least part of sensory nerves located within a target area while maintaining functional activity of tissue surrounding the sensory nerves by means of shielding it from the effects of laser radiation. According to some embodiments, the sensory nerves include neurons configured to transmit signals triggered by food passing through the duodenum, such as, but not limited to, neurohormonal signals.